Optical device, display device, and method for manufacturing light emitting element

ABSTRACT

A display device includes a frame and an image display device. The image display device includes an image forming device, a light guide device, and a lens system. The image forming device includes light emitting elements 300 arranged in a two-dimensional matrix. Each of the light emitting elements 300 has a laminated structure 301 including at least one layer of light emitting laminates 310, 320, and 330 each including a first electrode, a second electrode, and a light emitting layer provided between the first electrode and the second electrode. The laminated structure 301 has a through hole 360 through which light from the light emitting layer is emitted toward the lens system. An antireflection layer 370 is formed in a portion of the laminated structure facing the lens system.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/768,247, filed Apr. 13, 2018, which is a U.S.National Phase of International Patent Application No. PCT/JP2016/075346filed Aug. 30, 2016, which claims priority benefit of Japanese PatentApplication No. JP 2015-211682 filed in the Japan Patent Office Oct. 28,2015. Each of the above-referenced applications is hereby incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to an optical device, a display device,and a method for manufacturing a light emitting element.

BACKGROUND ART

A display device for causing an observer to observe a two-dimensionalimage formed by an image forming device as an enlarged virtual image bya virtual image optical system is well known from, for example, JapanesePatent Application Laid-Open No. 2007-309045. As illustrated in theconceptual diagram of FIG. 34, the display device includes an imageforming device 911 including a liquid crystal display device having aplurality of pixels arranged in a two-dimensional matrix, a lens system114 on which an image emitted from the image forming device 911 isincident, and a light guide device 120 on which an image emitted fromthe lens system 114 is incident, which guides light, and which emits thelight. The light guide device 120 includes: a light guide plate 121 fromwhich light incident on the light guide device 120 is emitted after thelight is propagated by total reflection inside the light guide device120; a first deflecting unit 122 for reflecting light incident on thelight guide plate 121 such that the light incident on the light guideplate 121 is totally reflected inside the light guide plate 121; and asecond deflecting unit 123 for emitting the light propagated by totalreflection inside the light guide plate 121 from the light guide plate121. In addition, if such a display device constitutes, for example, ahead mounted display (HMD), the weight and size of the device can bereduced. Each of the first deflecting unit 122 and the second deflectingunit 123 includes, for example, a reflection type volume hologramdiffraction grating. In addition, by displaying an image on the displaydevice, an observer 20 can view the displayed image superimposed on animage of an outside world. Incidentally, for the other referencenumerals in FIG. 34, refer to reference numerals in a display devicedescribed in Example 1.

CITATION LIST Patent Document

Patent Document 1: Japanese Patent Application Laid-Open No. 2007-309045

Patent Document 2: Japanese Translation of PCT International ApplicationNo. 2010-541248

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

By the way, when light emitted from the image forming device 911 isincident on the lens system 114 located near the image forming device911, a part of the light is reflected on a surface of the lens system114 on a side of the image forming device, and is returned to the imageforming device 911. Note that such light is referred to as “returnlight” for convenience. An antireflection film is formed on a surface ofthe lens system 114, but such return light is still generated. Then, aphenomenon that such return light is reflected on a surface of the imageforming device 911 and is incident on the lens system 114 again mayoccur. Such a phenomenon has a large adverse influence on HMD in which adisplayed image superimposed on an image of an outside world is viewed.That is, when such a phenomenon occurs, extra light enters an imageobserved by the observer 20, and therefore image quality isdeteriorated. According to the technology disclosed in theabove-described patent publication, by appropriately disposing the imageforming device 911 and the light guide device 120, it is possible toeffectively prevent light which is emitted from the image forming device911, passes through the lens system 114, is incident on the light guidedevice 120, and is reflected by the light guide device 120 fromreturning to the image forming device 911. However, the above-describedpatent publication does not describe anything about technology forpreventing light reflected by the lens system 114 from returning to theimage forming device 911, being reflected by the image forming device911, and being incident on the lens system 114 again.

Therefore, an object of the present disclosure is to provide an opticaldevice and a display device having a configuration and a structurecapable of preventing a part of light emitted from an image formingdevice from being reflected by a lens system, returning to an imageforming device, being reflected by the image forming device, and beingincident on the lens system again, and a method for manufacturing alight emitting element constituting the optical device or the displaydevice.

Solutions to Problems

In order to achieve the above object, an optical device of the presentdisclosure is an optical device including:

-   an image forming device; and-   a lens system for projecting an image from the image forming device    on an outside, in which-   the image forming device includes light emitting elements arranged    in a two-dimensional matrix,-   each of the light emitting elements has a laminated structure    including at least one layer of a light emitting laminate including    a first electrode, a second electrode, and a light emitting layer    provided between the first electrode and the second electrode,-   the laminated structure has a through hole which is formed in a    lamination direction of the laminated structure and through which    light from the light emitting layer is emitted toward the lens    system, and-   an antireflection layer is formed in a portion of the laminated    structure facing the lens system.

In order to achieve the above object, a display device of the presentdisclosure is a display device including:

-   (a) a frame mounted on the head of an observer; and-   (b) an image display device attached to the frame, in which-   the image display device includes:-   (A) an image forming device;-   (B) a light guide device for guiding an image from the image forming    device to the pupil of an observer; and-   (C) a lens system for making an image from the image forming device    incident on the light guide device,-   the image forming device includes light emitting elements arranged    in a two-dimensional matrix,-   each of the light emitting elements has a laminated structure    including at least one layer of a light emitting laminate including    a first electrode, a second electrode, and a light emitting layer    provided between the first electrode and the second electrode,-   the laminated structure has a through hole which is formed in a    lamination direction of the laminated structure and through which    light from the light emitting layer is emitted toward the lens    system, and-   an antireflection layer is formed in a portion of the laminated    structure facing the lens system.

In order to achieve the above object, a method for manufacturing a lightemitting element of the present disclosure includes steps of:

-   forming a laminated structure including at least one layer of a    light emitting laminate including a first electrode, a second    electrode, and a light emitting layer provided between the first    electrode and the second electrode; then forming an antireflection    layer on the laminated structure; and-   then forming a through hole for emitting light from the light    emitting layer toward an outside in the antireflection layer and the    laminated structure in a lamination direction of the laminated    structure.

Effects of the Invention

In the optical device or the display device of the present disclosure,an antireflection layer is formed in a portion of the laminatedstructure facing the lens system. In addition, in the method formanufacturing a light emitting element of the present disclosure, athrough hole is formed in the antireflection layer and the laminatedstructure. Therefore, even when a part of light emitted from the imageforming device is reflected by the lens system and is returned to theimage forming device, the light is not reflected by the image formingdevice, and it is possible to reliably prevent extra light from enteringan image observed by an observer, and it is possible to obtain an imagewith high image quality. Note that effects described herein are merelyillustrative, and are not restrictive. Furthermore, an additional effectmay be present.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic partial cross-sectional view obtained by cutting alight emitting element constituting a display device of Example 1 alonga virtual vertical plane.

FIG. 2 is a schematic partial cross-sectional view obtained by cuttingthe light emitting element constituting the display device of Example 1along a virtual vertical plane different from that in FIG. 1.

FIG. 3 is a schematic partial cross-sectional view obtained by cuttingthe light emitting element constituting the display device of Example 1along a virtual vertical plane different from those in FIGS. 1 and 2.

FIG. 4 is a schematic partial cross-sectional view obtained by cuttingthe light emitting element constituting the display device of Example 1along a virtual vertical plane different from those in FIGS. 1, 2, and3.

FIG. 5 is a schematic partial cross-sectional view obtained by cuttingthe light emitting element constituting the display device of Example 1along a virtual vertical plane different from those in FIGS. 1, 2, 3,and 4.

FIG. 6 is a schematic partial cross-sectional view obtained by cuttingthe light emitting element constituting the display device of Example 1along a virtual vertical plane different from those in FIGS. 1, 2, 3, 4,and 5.

FIG. 7 is a schematic partial plan view of the light emitting elementconstituting the display device of Example 1 as viewed from a side of alens system.

FIG. 8 is a schematic partial cross-sectional view obtained by cuttingthe light emitting element constituting the display device of Example 1along a virtual horizontal plane along arrow A-A in FIG. 1.

FIG. 9 is a schematic partial plan view of the light emitting elementconstituting the display device of Example 1 as viewed from the oppositeside to the side of the lens system.

FIG. 10 is a conceptual diagram of an image forming device of Example 1.

FIG. 11 is a schematic view of the display device of Example 1 as viewedfrom above.

FIG. 12 is a schematic view of the display device of Example 1 as viewedfrom the front.

FIGS. 13A, 13B, and 13C are a schematic view of the display device ofExample 1 as viewed from a side, a diagram schematically illustrating apropagation state of light in a light guide plate constituting an imagedisplay device, and a schematic cross-sectional view illustrating a partof a reflection type volume hologram diffraction grating in an enlargedmanner, respectively.

FIG. 14 is a conceptual diagram of an image forming device of Example 2.

FIG. 15 is a schematic view of a display device of Example 3 as viewedfrom the front.

FIG. 16 is a schematic view of the display device of Example 3 as viewedfrom above.

FIG. 17 is a schematic view of a display device of Example 4 as viewedfrom above.

FIG. 18 is a conceptual diagram of an image display device in a displaydevice of Example 5.

FIG. 19 is a schematic view of the display device of Example 5 as viewedfrom above.

FIG. 20 is a schematic view of the display device of Example 5 as viewedfrom a side.

FIG. 21 is a conceptual diagram of a modified example of the imagedisplay device in the display device of Example 5.

FIG. 22 is a conceptual diagram of an image display device in a displaydevice of Example 6.

FIG. 23 is a schematic view of the display device of Example 6 as viewedfrom above.

FIGS. 24A and 24B are a schematic view of the display device of Example6 as viewed from a side and a schematic view of portions of a lightguide device and a light control device in the display device of Example6 as viewed from the front, respectively.

FIGS. 25A and 25B are a schematic cross-sectional view of the lightcontrol device in the display device of Example 6 and a schematic frontview of the light control device, respectively.

FIGS. 26A, 26B, and 26C are diagrams schematically illustrating a changein a virtual image projection region of a light control device and thelike.

FIG. 27 is a diagram schematically illustrating a virtual rectanglecircumscribed with a virtual image formed in a light guide device and arectangular shape of a virtual image projection region of a lightcontrol device.

FIGS. 28A and 28B are a schematic view of a display device of Example 7as viewed from above and a schematic diagram of a circuit forcontrolling an environmental illuminance measuring sensor, respectively.

FIGS. 29A and 29B are a schematic view of a display device of Example 8as viewed from above and a schematic diagram of a circuit forcontrolling a transmitted light illuminance measuring sensor,respectively.

FIG. 30 is a conceptual diagram of an optical device (projector) ofExample 9.

FIG. 31 is a schematic partial cross-sectional view obtained by cuttinga light emitting element constituting a modified example of the displaydevice of Example 1 along a virtual vertical plane.

FIG. 32 is a schematic partial cross-sectional view obtained by cuttinga light emitting element constituting another modified example of thedisplay device of Example 1 along a virtual vertical plane.

FIG. 33A is a schematic view of a light guide device in a modifiedexample of the display device of Example 4 as viewed from above. FIGS.33B and 330 are a schematic view of a light guide device in anothermodified example of the display device of Example 4 as viewed from aboveand a schematic view thereof as viewed from the front, respectively.

FIG. 34 is a conceptual diagram of a conventional image display device.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present disclosure will be described on the basis ofExamples with reference to the drawings. However, the present disclosureis not limited to Examples, but various numerical values and materialsin Examples are illustrative. Note that description will be made in thefollowing order.

-   1. General description on optical device and display device of the    present disclosure, and method for manufacturing light emitting    element of the present disclosure-   2. Example 1 (display device of the present disclosure, method for    manufacturing light emitting element of the present disclosure, and    light guide device of first-A configuration)-   3. Example 2 (modification of Example 1 and light guide device of    first-B configuration)-   4. Example 3 (another modification of Example 1 and light guide    device of second configuration)-   5. Example 4 (still another modification of Example 1 and light    guide device of second configuration)-   6. Example 5 (modification of Examples 1 to 3 and light shielding    member)-   7. Example 6 (modification of Examples 1 to 5 and light control    device)-   8. Example 7 (modification of Example 6)-   9. Example 8 (another modification of Example 6)-   10. Example 9 (optical device of the present disclosure)-   11. Others

<General Description on Optical Device and Display Device of the PresentDisclosure, and Method for Manufacturing Light Emitting Element of thePresent Disclosure>

In a light emitting element constituting an optical device or a displaydevice of the present disclosure, an antireflection layer may be formedup to an edge portion of a through hole in a laminated structure. Thatis, when the light emitting element is viewed from a lens system, topsurfaces of the antireflection layer and the through hole are visuallyrecognized. More specifically, when the light emitting element is viewedfrom the lens system, the top surfaces of the antireflection layer andthe through hole are visually recognized, and a top surface of thelaminated structure is not visually recognized. In a light emittingelement obtained by a method for manufacturing a light emitting elementof the present disclosure, an antireflection layer is naturally formedup to an edge portion of a through hole in a laminated structure due tothe manufacturing method. Incidentally, if an antireflection layer isformed even above a through hole, emitting of light from the throughhole is hindered by the antireflection layer.

In the optical device or the display device of the present disclosureincluding the above preferable form, or in a light emitting elementobtained by the method for manufacturing a light emitting element of thepresent disclosure, a light emitting element may have a laminatedstructure including three layers of a light emitting laminate that emitsred light, a light emitting laminate that emits green light, and a lightemitting laminate that emits blue light. The laminating order of thesethree light emitting laminates is essentially arbitrary.

Furthermore, in the optical device or the display device of the presentdisclosure including the above preferable form, or in a light emittingelement obtained by the method for manufacturing a light emittingelement of the present disclosure including the above preferable form, alight emitting element may further include a condenser lens forcondensing light emitted from a through hole. Examples of a materialconstituting the condenser lens include an acrylic resin, an epoxyresin, and a silicone rubber. Examples of a method for forming(disposing) a condenser lens include a reflow method, a potting method,an imprinting method, a photolithography method, an etching method, anda printing method.

Furthermore, in the optical device or the display device of the presentdisclosure including the above preferable form, or in a light emittingelement obtained by the method for manufacturing a light emittingelement of the present disclosure including the above preferable form,an image forming device may further include a circuit board on which alight emitting element driving circuit is provided, and each lightemitting element may be connected to the light emitting element drivingcircuit provided on a circuit board.

Furthermore, in the optical device or the display device of the presentdisclosure including the above preferable form, or in a light emittingelement obtained by the method for manufacturing a light emittingelement of the present disclosure including the above preferable form,an image forming device may further include a support substrateconstituting a laminated structure on a light emitting side.Incidentally, in this case, an antireflection layer is formed on asurface of the support substrate (surface facing a lens system).

Specifically, for example, Japanese Translation of PCT InternationalApplication No. 2010-541248 discloses a light emitting element having alaminated structure including at least one layer of a light emittinglaminate including a first electrode, a second electrode, and a lightemitting layer provided between the first electrode and the secondelectrode, the laminated structure having a through hole formed in alamination direction of the laminated structure.

An antireflection layer is formed in a portion of the laminatedstructure or a support substrate facing a lens system. However, in oneform, the antireflection layer is formed on (on a top surface of) thelaminated structure or the support substrate. In such a form, examplesof a material constituting the antireflection layer include carbon, ametal thin film (for example, chromium, nickel, aluminum, molybdenum, oran alloy thereof), a metal oxide (for example, chromium oxide), a metalnitride (for example, chromium nitride), an organic resin, a glasspaste, a glass paste containing conductive particles of a black pigment,silver, or the like, a black dye, and various inks (paints). Specificexamples thereof include a photosensitive polyimide resin layer, achromium oxide layer, and a chromium oxide/chromium laminated structure.In addition, the antireflection layer can be formed on the basis of amethod appropriately selected depending on a material to be used, suchas a vacuum deposition method, a sputtering method, a spin coatingmethod, various printing methods including an inkjet printing method, aplating method, or a lithography technique. In addition, in anotherform, an antireflection layer is formed on a laminated structure or asupport substrate. In such a form, the antireflection layer may have amoth-eye structure or a fine uneven structure. Specifically, theantireflection layer may have a structure in which a surface of alaminated structure or a support substrate is subjected to unevenprocessing, for example, on the basis of an etching technique to formunevenness on a surface of the laminated structure or the supportsubstrate. Furthermore, these structures may be appropriately combinedwith each other.

If light reflectance obtained when visible light (wavelength 400 nm to700 nm) is incident on a laminated structure or a support substratehaving no antireflection layer formed thereon at a predetermined angleof incidence is represented by R₀, and light reflectance obtained whenlight is incident on a laminated structure or a support substrate havingan antireflection layer formed thereon at a predetermined angle ofincidence is represented by R₁, a value of R₁/R₀ is 0.5 or less, anddesirably 0.1 or less. Note that it is only required to measure lightreflectance on the basis of a method described in JIS 28722:2009 5.3“Method for measuring reflective object”.

Examples of the support substrate include: a transparent inorganicsubstrate such as a silicon semiconductor substrate, a substrateincluding a group III-V semiconductor (specifically, GaAs, InP, GaN,AlN, GaP, GaSb, and InAs as a substrate including a III-V groupsemiconductor), a sapphire substrate, a SiC substrate, a glass substrate(for example, a soda glass substrate, a heat-resistant glass substrate,or a quartz glass substrate), or a quartz substrate; and a transparentplastic substrate or a film (a polyester resin such as polyethyleneterephthalate (PET) or polyethylene naphthalate (PEN); a polycarbonate(PC) resin; a polyether sulfone (PES) resin; a polyolefin resin such aspolystyrene, polyethylene, or polypropylene; a polyphenylene sulfideresin; a polyvinylidene fluoride resin; a tetraacetyl cellulose resin; abrominated phenoxy resin; an aramid resin; a polyimide resin; apolystyrene resin; a polyarylate resin; a polysulfone resin; an acrylicresin; an epoxy resin; a fluorocarbon resin; a silicone resin; adiacetate resin; a triacetate resin; a polyvinyl chloride resin; acyclic polyolefin resin; and the like). Examples of a second supportsubstrate described later include a silicon semiconductor substrate anda substrate including a III-V group semiconductor.

Examples of a circuit board on which a light emitting element drivingcircuit is provided include a silicon semiconductor substrate. It isonly required to constitute the light emitting element driving circuitby a well-known driving circuit suitable for driving a light emittingelement. Examples of a method for connecting a light emitting element toa light emitting element driving circuit provided on a circuit boardinclude [A] a method for connecting these using a bump (that is, amethod for connecting a contact portion provided in an image formingdevice and extending from a light emitting element to a connectionportion including a bump portion provided on a circuit board, referredto as a flip-chip connection method), [B] a metal bonding method forconnecting a contact portion provided in an image forming device andincluding copper (Cu) extending from a light emitting element to aconnection portion provided on a circuit board and including copper(Cu), and [C] a connection method using through contact VIA (TCV). Notethat it is only required to provide the contact portion, for example, ona second support substrate described later.

The laminated structure of the light emitting laminate itself includingthe first electrode, the second electrode, and the light emitting layerprovided between the first electrode and the second electrode may be awell-known laminated structure. A method for manufacturing the laminatedstructure may be a well-known manufacturing method. The light emittinglayer has a structure in which a plurality of compound semiconductorlayers is laminated.

Examples of a layer configuration of a light emitting layer constitutingthe light emitting laminate that emits red light include a buffer layerincluding n-type GaAs and first compound semiconductor layer (forexample, including a first clad layer including n-type AlGaAs)/activelayer including GaAs, AlGaAs, or AlGaInP/second compound semiconductorlayer (for example, including a second clad layer including p-typeAlGaAs and a cap layer including p-type GaAs). However, the layerconfiguration is not limited to such a layer configuration. In addition,examples of a layer configuration of a light emitting layer constitutingthe light emitting laminate that emits green or blue light include afirst compound semiconductor layer (for example, including an n-typeAlGaN clad layer and an n-type GaN clad layer)/InGaN quantum well activelayer/second compound semiconductor layer (for example, including anon-doped InGaN light guide layer, a p-type AlGaN electron barrierlayer, a p-type GaN/AlGaN superlattice clad layer, and a p-type GaNcontact layer). However, the layer configuration is not limited to sucha layer configuration.

Examples of various compound semiconductor layers constituting a lightemitting layer include a GaN-based compound semiconductor (including anAlGaN mixed crystal, an AlInGaN mixed crystal, or an InGaN mixedcrystal), an InGaNAs-based compound semiconductor (including a GaInAsmixed crystal or a GaNAs mixed crystal), an AlGaInP-based compoundsemiconductor, an AlAs-based compound semiconductor, an AlGaInAs-basedcompound semiconductor, an AlGaAs-based compound semiconductor, aGaInAs-based compound semiconductor, a GaInAsP-based compoundsemiconductor, a GaInP-based compound semiconductor, a GaP-basedcompound semiconductor, an InP-based compound semiconductor, anInN-based compound semiconductor, and an AlN-based compoundsemiconductor. Examples of an n-type impurity added to a compoundsemiconductor layer include silicon (Si), selenium (Se), germanium (Ge),tin (Sn), carbon (C), and titanium (Ti). Examples of a p-type impurityinclude zinc (Zn), magnesium (Mg), beryllium (Be), cadmium (Cd), calcium(Ca), and barium (Ba), and oxygen (O). An active layer constituting alight emitting layer may include a single compound semiconductor layer,or may have a single quantum well structure (SQW structure) or amultiple quantum well structure (MQW structure). Examples of a methodfor forming a light emitting layer (film formation method) include ametal organic-chemical vapor deposition method (MOCVD method), a metalorganic-vapor phase epitaxy method (MOVPE method), a molecular beamepitaxy method (MBE method), a hydride vapor phase epitaxy method (HVPEmethod) in which a halogen contributes to transport or a reaction, aplasma assisted physical vapor deposition method (PPD method), an atomiclayer deposition method (ALD method), and a migration-enhanced epitaxy(MEE) method. However, the method is not limited thereto.

Here, in a case where a light emitting laminate that emits green lightand a light emitting laminate that emits blue light are formed by aMOCVD method, examples of a gas used include a trimethylgallium (TMG)gas, a triethylgallium (TEG) gas, a trimethylaluminum (TMA) gas, atrimethylindium (TMI) gas, and arsine (AsH₃). Examples of a nitrogensource gas include an ammonia gas and a hydrazine gas. In addition, forexample, in a case where silicon (Si) is added as an n-type impurity(n-type dopant), it is only required to use a monosilane gas (SiH₄ gas)as a Si source. In a case where selenium (Se) is added as an n-typeimpurity (n-type dopant), it is only required to use a H₂Se gas as a Sesource. Meanwhile, in a case where magnesium (Mg) is added as a p-typeimpurity (p-type dopant), it is only required to use a cyclopentadienylmagnesium gas, methylcyclopentadienyl magnesium, or biscyclopentadienylmagnesium (Cp₂Mg) as a Mg source. In a case where zinc (Zn) is added asa p-type impurity (p-type dopant), it is only required to use dimethylzinc (DMZ) as a Zn source. Incidentally, examples of the n-type impurity(n-type dopant) further include Ge, Se, Sn, C, and Ti in addition to Si,and examples of the p-type impurity (p-type dopant) further include Zn,Cd, Be, Ca, Ba, and 0 in addition to Mg. In addition, in the lightemitting laminate that emits red light, examples of a gas used includetrimethyl aluminum (TMA), triethyl aluminum (TEA), trimethyl gallium(TMG), triethyl gallium (TEG), trimethyl indium (TMI), triethyl indium(TED, phosphine (PH₃), arsine (AsH₃), dimethylzinc (DMZ), diethylzinc(DEZ), H₂S, hydrogen selenide (H₂Se), and biscyclopentane diethylzinc.

In a case of forming a laminated structure of a plurality of lightemitting laminates (for example, a first light emitting laminate, asecond light emitting laminate, and a third light emitting laminate), amethod for sequentially forming the first light emitting laminate, thesecond light emitting laminate, and the third light emitting laminate ona light emitting laminate manufacturing substrate (corresponding to asupport substrate) may be adopted. Alternatively, the following methodmay be adopted. That is, in advance, a first light emitting laminate isformed on a first light emitting laminate manufacturing substrate, asecond light emitting laminate is formed on a second light emittinglaminate manufacturing substrate, and a third light emitting laminate isformed on a third light emitting laminate manufacturing substrate. Then,after the first light emitting laminate is laminated on a supportsubstrate, the first light emitting laminate manufacturing substrate isremoved, and the second light emitting laminate is laminated on thefirst light emitting laminate. Thereafter, the second light emittinglaminate manufacturing substrate is removed, and the third lightemitting laminate is laminated on the second light emitting laminate.Thereafter, the third light emitting laminate manufacturing substrate isremoved, and a second support substrate is laminated on the third lightemitting laminate. In a case of laminating, a short-circuit betweenelectrodes may be prevented by interposing an insulating layer. Theinsulating layer may include a well-known insulating material such assilicon oxide (SiOx), silicon nitride (SiN_(Y)), silicon oxynitride(SiO_(X)N_(Y)), tantalum oxide (Ta₂O₅), zirconium oxide (ZrO₂), aluminumoxide (Al₂O₃), aluminum nitride (AlN), titanium oxide (TiO₂), magnesiumoxide (MgO), chromium oxide (CrO_(x)), vanadium oxide (VO_(x)), ortantalum nitride (TaN).

Examples of a method for removing a light emitting laminatemanufacturing substrate include a laser ablation method and a heatingmethod in addition to a wet etching method and a dry etching method.Examples of a method for laminating a light emitting laminate on asupport substrate and a method for laminating a light emitting laminateon a light emitting laminate include a method using an adhesive, a metalbonding method, a semiconductor bonding method, a metal/semiconductorbonding method, a diffusion bonding method, and an anode bonding method.

Examples of the light emitting laminate manufacturing substrate, thefirst light emitting laminate manufacturing substrate, the second lightemitting laminate manufacturing substrate, and the third light emittinglaminate manufacturing substrate include a GaN substrate, an AlGaNsubstrate, an InGaN substrate, an AlInGaN substrate, an InN substrate,an AlInN substrate, a GaAs substrate, a GaP substrate, an InGaPsubstrate, an AlInGaP substrate, an AlP substrate, an AlGaP substrate,an AlInP substrate, an InP substrate, a sapphire substrate, a SiCsubstrate, an alumina substrate, a ZnS substrate, a ZnO substrate, anAlN substrate, a LiMgO substrate, a LiGaO₂ substrate, a MgAl₂O₄substrate, a Si substrate, a Ge substrate, and those obtained by formingan underlayer or a buffer layer on surfaces (main surfaces) of thesesubstrates. In a case of forming a GaN-based compound semiconductorlayer on a substrate, use of a GaN substrate is preferable because of alow defect density. It is known that characteristics of the GaNsubstrate change among polar/nonpolar/semipolar properties depending ona growth surface. However, any main surface of the GaN substrate can beused for forming a compound semiconductor layer. For a main surface of asubstrate, some crystal structures (for example, a cubic type or ahexagonal type) can use a crystal orientation plane referred to asso-called A plane, B plane, C plane, R plane, M plane, N plane, S plane,or the like, planes obtained by turning off these planes in a specificdirection, and the like.

For example, the first electrode desirably has a single layerconfiguration or a multilayer configuration including at least one metal(including an alloy) selected from the group consisting of gold (Au),silver (Ag), palladium (Pd), platinum (Pt), nickel (Ni), Ti (titanium),vanadium (V), tungsten (W), chromium (Cr), Al (aluminum), Cu (copper),Zn (zinc), tin (Sn), and indium (In). Specific examples thereof includeTi/Au, Ti/Al, Ti/Al/Au, Ti/Pt/Au, Ni/Au, Ni/Au/Pt, Ni/Pt, Pd/Pt, Ag/Pd,and Sn/Au. Incidentally, the further forward a layer in “/” of themultilayer configuration is located, the closer to a light emittinglayer the layer is located. For example, the second electrode may have asingle layer configuration or a multilayer configuration including atleast one metal (including an alloy) selected from the group consistingof palladium (Pd), nickel (Ni), platinum (Pt), gold (Au), cobalt (Co),and rhodium (Rh) (for example, a laminated structure of palladiumlayer/platinum layer in which the palladium layer is in contact with asecond compound semiconductor layer or a laminated structure ofpalladium layer/nickel layer in which the palladium layer is in contactwith a second compound semiconductor layer).

The above-described contact portion desirably has a single layerconfiguration or a multilayer configuration including at least one metalselected from the group consisting of Ti (titanium), aluminum (Al), Pt(platinum), Au (gold), Ni (nickel), Pd (palladium), and copper (Cu).Alternatively, the contact portion may have a multilayer configurationsuch as a Ti/Pt/Au multilayer configuration, a Ti/Au multilayerconfiguration, a Ti/Pd/Au multilayer configuration, a Ti/Pd/Aumultilayer configuration, a Ti/Ni/Au multilayer configuration, or aTi/Ni/Au/Cr/Au multilayer configuration. In some cases, a connectionportion provided on the above-described circuit board for connecting thecontact portion to the first electrode or the second electrode onlyneeds to be selected appropriately from materials constituting the firstelectrode, the second electrode, and the contact portion.

The first electrode, the second electrode, and the contact portion canbe formed by various PVD methods, various CVD methods, or a platingmethod. Here, examples of the PVD method include (a) various vacuumvapor deposition methods such as an electron beam heating method, aresistance heating method, a flash vapor deposition method, and pulselaser deposition (PLD method), (b) a plasma vapor deposition method, (c)various sputtering methods such as a dipole sputtering method, a directcurrent sputtering method, a direct current magnetron sputtering method,a high frequency sputtering method, a magnetron sputtering method, anion beam sputtering method, and a bias sputtering method, (d) variousion plating methods such as a direct current (DC) method, an RF method,a multi-cathode method, an activation reaction method, a hollow cathodedischarge (HCD) method, an electric field vapor deposition method, ahigh frequency ion plating method, and a reactive ion plating method,and (e) an ion vapor deposition method (IVD method). In addition,examples of the CVD method include an atmospheric pressure CVD method, areduced pressure CVD method, a thermal CVD method, a plasma CVD method,a photo CVD method, and a laser CVD method.

Examples of a method for patterning the first compound semiconductorlayer, the active layer, the second compound semiconductor layer, thefirst electrode, the second electrode, and the contact portion include adry etching method such as an RIE method and a wet etching method.

If light is emitted in a light emitting laminate, an evanescent field isformed in a boundary region between the light emitting laminate and athrough hole. That is, light penetrates through an inside of a throughhole that reflects light under a specific condition in a reflectionphenomenon of light. This light which has penetrated is called anevanescent field. Light emitted from the evanescent field is calledevanescent light or near-field light. In the optical device or thedisplay device of the present disclosure, a light emitting element emitsthe evanescent light (near-field light) to the lens system, and an imageis displayed.

The through hole (vertical waveguide) formed in a laminated structure ina lamination direction of the laminated structure can be formed by a dryetching method such as RIE method, for example. Examples of across-sectional shape of the through hole (cross-sectional shapeobtained by cutting the through hole with a virtual vertical planeperpendicular to a direction in which the through hole extends (virtualhorizontal plane)) include a circle. A side surface of the through holecan be vertical or can have a tapered shape extending to a lightemitting side. The through hole may include a core portion and a cladlayer disposed between the laminated structure and the core portion. Thecore portion is filled, for example, with air or a dielectric materialsuch as SiO₂, SiN, or Ta₂O₅. Meanwhile, the clad layer includes, forexample, an outer clad layer (layer in contact with the laminatedstructure) including an insulating material such as SiO₂ and an innerclad layer (layer facing the core portion) including a light-reflectingmetal such as aluminum (Al), silver (Ag), or gold (Au). Alternatively,for example, the through hole may be a through hole in which the coreportion includes TiO₂ and the clad layer includes SiO₂, or for example,the through hole may be a through hole in which the core portionincludes TiO₂, the inner clad layer includes SiO₂,and the outer cladlayer includes SiN. Alternatively, a polydiacetylene-based compoundlayer or a polydithienothiophene-based compound layer may be disposedbetween the laminated structure and the clad layer, and this makes itpossible to reduce power consumption of a light emitting element. Inaddition, the core portion does not have to fill all the through holes.That is, the core portion may be formed in a light emitting layer of alight emitting laminate, or in a region of a through hole facing a lightemitting layer and the vicinity thereof.

The optical device of the present disclosure can constitute a so-calledprojector. That is, by connecting the optical device of the presentdisclosure to a DVD player or a personal computer, an image can beprojected on a screen on the basis of an image signal output from theDVD player or the personal computer. Alternatively, the optical deviceof the present disclosure can be used as a displaying device in which anobserver directly observes an image emitted from the optical device ofthe present disclosure, and in this case, a lens system may beunnecessary. Furthermore, the optical device of the present disclosurecan constitute a part of the display device of the present disclosure.

The display device of the present disclosure can constitute, forexample, a head mounted display (HMD). In addition, this makes itpossible to reduce the weight and size of the display device, to largelyreduce discomfort when the display device is mounted, and further toreduce manufacturing cost. The display device of the present disclosurecan also be used as a stereoscopic displaying device. In this case, ifnecessary, it is only required to detachably attach a polarizing plateor a polarizing film to a light guide plate described later, or to bondthe polarizing plate or the polarizing film to the light guide plate.

Examples of the number of pixels (the number of light emitting elements)of the optical device or the display device of the present disclosureinclude 320×240, 432×240, 640×480, 854×480, 1024×768, and 1920×1080.

A light guide device constituting the display device of the presentdisclosure can include, for example, a light guide plate, a firstdeflecting unit, and a second deflecting unit. The first deflecting unitand the second deflecting unit are attached to the light guide plate.Light which has been emitted from the image forming device and haspassed through the lens system is incident on the first deflecting unit.Then, the light deflected by the first deflecting unit repeats totalreflection inside the light guide plate, is deflected by the seconddeflecting unit, is emitted from the light guide plate, and reaches thepupil of an observer. Note that the light guide device having such astructure is referred to as a “light guide device of a firstconfiguration” for convenience. Here, the term “total reflection” meanstotal internal reflection or total reflection inside the light guideplate. A virtual image forming region of the light guide device isconstituted by the second polarizing unit.

Alternatively, the light guide device may include a semi-transmissivemirror or a polarizing beam splitter (PBS) that receives light emittedfrom the image forming device and emits the light toward the pupil of anobserver. In the former configuration, light forms an image directly onthe retina of an observer. The semi-transmissive mirror or thepolarizing beam splitter forms a virtual image forming region of thelight guide device. Light emitted from the image forming device may bepropagated in air to be incident on the semi-transmissive mirror or thepolarizing beam splitter. For example, the light may be propagatedinside a transparent member such as a glass plate to be incident on thesemi-transmissive mirror or the polarizing beam splitter. Thesemi-transmissive mirror or the polarizing beam splitter may be attachedto the image forming device via a transparent member, may be attached tothe image forming device via a member different from the transparentmember, or may be provided inside the transparent member. Alternatively,the light guide device may include a prism on which light emitted fromthe image forming device is incident and from which the light is emittedtoward the pupil of an observer. Note that the light guide device havingvarious structures described above is referred to as a “light guidedevice of a second configuration” for convenience.

Hereinafter, the light guide device of the first configuration will bedescribed.

Specifically, the light guide device of the first configuration includesa first deflecting unit for deflecting light incident from a lenssystem, a light guide plate for propagating the light deflected by thefirst deflecting unit by total reflection therein, and a seconddeflecting unit for deflecting and emitting the light propagated bytotal reflection inside the light guide plate. The light guide plate maybe disposed so as to face an image forming device with the lens systeminterposed therebetween.

Each of the first deflecting unit and the second deflecting unit mayinclude a hologram diffraction grating. Such a light guide device of thefirst configuration is referred to as a “light guide device of a first-Aconfiguration” for convenience. The hologram diffraction grating may beconstituted by a reflection type hologram diffraction grating or atransmission type hologram diffraction grating. Alternatively, in a casewhere a deflecting unit includes a plurality of hologram diffractiongratings, some of the hologram diffraction gratings may be constitutedby a reflection type hologram diffraction grating, and the otherhologram diffraction gratings may be constituted by a transmission typehologram diffraction grating. In the hologram diffraction grating,incident light is diffracted and reflected. Note that examples of thereflection type hologram diffraction grating include a reflection typevolume hologram diffraction grating. The reflection type volume hologramdiffraction grating means a hologram diffraction grating that diffractsand reflects only +1st order diffracted light. In addition, in thefollowing description, a first deflecting unit or the like including areflection type volume hologram diffraction grating may be referred toas a “first diffraction grating member” for convenience, and a seconddeflecting unit or the like including a reflection type volume hologramdiffraction grating may be referred to as a “second diffraction gratingmember” for convenience.

The image display device in the present disclosure can display an imageof a single color (for example, green). In addition, in this case,although not limited, for example, by dividing an angle of view into two(more specifically, for example, by dividing the angle of view into twoequal parts), each of the first diffraction grating member and thesecond diffraction grating member can be formed by laminating twodiffraction grating members corresponding to groups of the angle of viewdivided into two. Alternatively, in a case where a color image isdisplayed, each of the first diffraction grating member and the seconddiffraction grating member can be formed by laminating P diffractiongrating layers each including a reflection type volume hologramdiffraction grating so as to correspond to diffraction reflection of Ptypes of light having different P types (for example, P=3, and threetypes of red, green, and blue) of wavelength bands (or wavelengths). Ineach diffraction grating layer, an interference fringe corresponding toone type of wavelength band (or wavelength) is formed. Alternatively,each of the first diffraction grating member and the second diffractiongrating member each including one diffraction grating layer may have Ptypes of interference fringes formed so as to correspond to diffractionreflection of P types of light having different P types of wavelengthbands (or wavelengths). Alternatively, for example, a diffractiongrating member including a diffraction grating layer including areflection type volume hologram diffraction grating for diffracting andreflecting light having a red wavelength band (or wavelength) may bedisposed on a first light guide plate, a diffraction grating memberincluding a diffraction grating layer including a reflection type volumehologram diffraction grating for diffracting and reflecting light havinga green wavelength band (or wavelength) may be disposed on a secondlight guide plate, a diffraction grating member including a diffractiongrating layer including a reflection type volume hologram diffractiongrating for diffracting and reflecting light having a blue wavelengthband (or wavelength) may be disposed on a third light guide plate, andthe first light guide plate, the second light guide plate, and the thirdlight guide plate may be stacked with a gap therebetween. Alternatively,for example, a diffraction grating member including a diffractiongrating layer including a reflection type volume hologram diffractiongrating for diffracting and reflecting light having a certain colorwavelength band (or wavelength) may be disposed on a first light guideplate, a diffraction grating member including a diffraction gratinglayer including a reflection type volume hologram diffraction gratingfor diffracting and reflecting light having another color wavelengthband (or wavelength) may be disposed on a second light guide plate, andthe first light guide plate and the second light guide plate may bestacked with a gap therebetween. Alternatively, for example, by dividingan angle of view into three equal parts, each of the first diffractiongrating member and the second diffraction grating member can be formedby laminating diffraction grating layers corresponding to the dividedangles of view. In addition, by adopting these configurations, it ispossible to increase diffraction efficiency, to increase a diffractionreception angle, and to optimize a diffraction angle when light havingeach wavelength band (or wavelength) is diffracted and reflected by thefirst diffraction grating member and the second diffraction gratingmember.

Examples of a method for manufacturing a diffraction grating memberinclude a method for forming a dry film-shaped photopolymer layer and amethod for forming a photopolymer layer sequentially on a supportincluding glass, plastic, or the like in a desired order on the basis ofa coating method. Examples of a method for coating a photopolymerinclude a known coating method such as a die coating method, a gravurecoating method, a roll coating method, a blade coating method, a curtaincoating method, a dip coating method, a spin coating method, or aprinting method. Incidentally, not only a single layer coating methodbut also a method for simultaneously coating a plurality of layers suchas a multilayer slide coating method can be adopted. A protective layer(spacer layer) may be disposed between photopolymer layers by awell-known coating means or a laminating method, as necessary.

In manufacturing a diffraction grating member, by irradiating aphotopolymer layer with a reference laser beam and an object laser beam,an interference fringe is recorded on a hologram material (photopolymer)on the basis of refractive index modulation. That is, an interferencefringe having a desired surface pitch ∧ and slant angle φ is formed.Specifically, for example, by irradiating a photopolymer layer with anobject laser beam from a first predetermined direction on one side, andat the same time, by irradiating the photopolymer layer with a referencelaser beam from a second predetermined direction on the other side, itis only required to record an interference fringe formed by the objectlaser beam and the reference laser beam inside the photopolymer layer.By appropriately selecting the first predetermined direction, the secondpredetermined direction, and the wavelengths of the object laser beamand the reference laser beam, it is possible to obtain a desired surfacepitch ∧ of an interference fringe in the photopolymer layer and adesired slant angle (inclination angle) of the interference fringe.Here, the slant angle of the interference fringe means an angle formedby a surface of a diffraction grating member and an interference fringe.In a case of forming a plurality of photopolymer layers, it is onlyrequired to distribute the photopolymer layers disposed on two lightguide plates. For example, in a case where it is necessary to form fourphotopolymer layers as a first diffraction grating member, it is onlyrequired to manufacture the four photopolymer layers by disposing twophotopolymer layers on each of the two light guide plates. This makes itpossible to secure manufacturing stability of optical characteristics ofa diffraction grating member. A photopolymer layer may be formed on eachof both surfaces of one light guide plate.

In order to protect a diffraction grating member, a transparentprotective member may be disposed. Specifically, an outer edge portionof a light guide plate and an outer edge portion of a transparentprotective member may be sealed with a sealing member, or may be bondedto each other. Examples of the sealing member also referred to as a sealagent include various resins including a thermosetting resin, aphotocurable resin, a moisture-curable resin, and an anaerobic curingresin, such as an epoxy resin, a urethane-based resin, an acrylic resin,a vinyl acetate-based resin, an ene-thiol-based resin, a silicone-basedresin, or a modified polymer resin.

Alternatively, the first deflecting unit may reflect light incident on alight guide plate, and the second deflecting unit may transmit, reflect,and diffract light propagated by total reflection inside the light guideplate a plurality of times. Such a light guide device of the firstconfiguration is referred to as a “light guide device of a first-Bconfiguration” for convenience. In addition, in this case, the firstdeflecting unit may function as a reflecting mirror, and the seconddeflecting unit may function as a semi-transmissive mirror.Specifically, for example, the first deflecting unit may include a metalincluding an alloy, may include a light reflecting film (a kind ofmirror) for reflecting light incident on a light guide plate, or mayinclude a multilayer film in which many dielectric laminated films arelaminated, a half mirror, or a polarizing beam splitter. In addition,the second deflecting unit may include a multilayer film in which manydielectric laminated films are laminated, a half mirror, a polarizingbeam splitter, or a hologram diffraction grating film. In addition, thefirst deflecting unit and the second deflecting unit are disposed insidea light guide plate (incorporated in the light guide plate). In thefirst deflecting unit, light incident on the light guide plate isreflected so as to be totally reflected inside the light guide plate.Meanwhile, in the second deflecting unit, light propagated by totalreflection inside the light guide plate is reflected or diffracted aplurality of times, and is emitted from the light guide plate.

Assuming a (X, Y, Z) orthogonal coordinate system, the light guide platehas two parallel surfaces (first surface and second surface) extendingparallel to an axis of the light guide plate (longitudinal direction andhorizontal direction, corresponding to an X axis direction). A widthdirection (height direction and vertical direction) of the light guideplate corresponds to a Z axis direction, and a normal line of the lightguide plate corresponds to a Y axis direction. An interference fringe ofa hologram diffraction grating extends substantially in parallel withthe Z axis direction. Examples of a material constituting the lightguide plate include various glasses including a quartz glass, an opticalglass such as BK7 or SK5, a soda lime glass (blue plate glass), a whiteplate glass, a borosilicate glass, various tempered glasses, and a glasswhich has been subjected to a chemical treatment (for example, Gorilla(registered trademark) and Eagle XG (registered trademark) availablefrom Corning Incorporated). By performing a chemical treatment, it ispossible to increase a specific ion density on a glass surface and tostrengthen a glass plate. Alternatively, examples of a materialconstituting the light guide plate include a plastic material (forexample, PMMA, a polycarbonate resin, an acrylic resin, an amorphouspolypropylene-based resin, or a styrene-based resin including an ASresin). The shape of the light guide plate is not limited to a flatplate, and may be a curved shape.

The first diffraction grating member may be attached to the secondsurface of the light guide plate, and the second diffraction gratingmember may be attached to the second surface of the light guide plate.The first diffraction grating member may be attached to the secondsurface of the light guide plate, and the second diffraction gratingmember may be attached to the first surface of the light guide plate.The first diffraction grating member may be attached to the firstsurface of the light guide plate, and the second diffraction gratingmember may be attached to the second surface of the light guide plate.The first diffraction grating member may be attached to the firstsurface of the light guide plate, and the second diffraction gratingmember may be attached to the first surface of the light guide plate.The first deflecting unit may include two first diffraction gratingmembers (first A diffraction grating member and first B diffractiongrating member). The first A diffraction grating member may be attachedto the first surface, and the first B diffraction grating member may beattached to the second surface. Alternatively, using two light guideplates, the first A diffraction grating member may be attached to one ofthe light guide plates, the first B diffraction grating member may beattached to the other light guide plate, and the second diffractiongrating member may be attached to either one of the light guide plates.That is, if a surface of a light guide plate on which light is firstincident is referred to as a light guide plate incidence surface and asurface of the light guide plate from which light is finally emitted isreferred to as a light guide plate emission surface, the first surfacemay constitute the light guide plate incidence surface and the lightguide plate emission surface, or the first surface may constitute thelight guide plate incidence surface and the second surface mayconstitute the light guide plate emission surface.

For convenience, if a surface of the light guide plate facing anobserver is the first surface, the image forming device and the lenssystem may be disposed on the first surface side or the second surfaceside of the light guide plate.

The lens system in the display device of the present disclosure is anoptical system for making light emitted from the image forming deviceparallel light. A request to make the light incident on the light guidedevice (light guide plate) parallel light is on the basis of a fact thatlight wavefront information when the light is incident on the lightguide device (light guide plate) needs to be stored even after beingemitted from the light guide device via the first deflecting unit andthe second deflecting unit. Incidentally, in order to generate parallellight, specifically, for example, it is only required to locate a lightemitting portion of the image forming device, for example, at a position(location) of a front focal point in the lens system. The lens systemhas a function of converting position information of a pixel into angleinformation in an optical system of the light guide device. Examples ofthe lens system include an optical system having a positive opticalpower as a whole, such as a convex lens, a concave lens, a free curedsurface prism, or a hologram lens, or a combination thereof. A lightshielding portion having an opening may be disposed between the lenssystem and the light guide device in order to prevent undesired lightemitted from the lens system from being incident on the light guidedevice.

In the light guide device of the first configuration in which the imageforming device and the lens system are disposed on the first surfaceside of the light guide plate, a light shielding member may be disposedoutside the second surface of the light guide plate so as to cover thefirst deflecting unit. In addition, in this case, an orthogonallyprojected image of the first deflecting unit on the light guide platemay be included in an orthogonally projected image of the lightshielding member on the light guide plate.

Alternatively, in the light guide device of the first configuration, alight shielding member for shielding incidence of external light on thelight guide device may be disposed in a region of the light guide deviceon which light emitted from the image forming device is incident. Bydisposing the light shielding member for shielding incidence of externallight on the light guide device in a region of the light guide device onwhich light emitted from the image forming device is incident, externallight is not incident on the region of the light guide device on whichlight emitted from the image forming device is incident. Therefore,image display quality is not deteriorated by generation of undesirablestray light or the like. Note that the region of the light guide deviceon which light emitted from the image forming device is incident ispreferably included in the orthogonally projected image of the lightshielding member on the light guide device.

Specifically, the light shielding member may be disposed on the secondsurface side of the light guide plate so as to be separated from thelight guide plate. In such a configuration, the light shielding membermay be manufactured, for example, from an opaque plastic material. Inaddition, such a light shielding member may integrally extend from acasing of the image display device, may be attached to the casing of theimage display device, may integrally extend from a frame, or may beattached to the frame. Alternatively, the light shielding member may beattached to the light guide plate, or may be attached to or disposed ina portion of the light guide plate on the opposite side to the sidewhere the image forming device is disposed. Alternatively, the lightshielding member may be disposed in a light control device describednext. In this case, an orthogonally projected image of an end portion ofthe light control device on the light guide plate is preferably includedin an orthogonally projected image of the light shielding member on thelight guide plate. For example, a light shielding member including anopaque material may be formed on a surface of the light guide plate onthe basis of a physical vapor deposition method (PVD method) or achemical vapor deposition method (CVD method), or a printing method. Afilm, a sheet, or a foil including an opaque material (plastic material,metal material, alloy material, or the like) may be bonded to thesurface of the light guide plate. A projected image of an end portion ofthe light control device on the light guide plate is preferably includedin a projected image of the light shielding member on the light guideplate. By inclusion of the light control device in this way, it ispossible to prevent occurrence of such a problem that sufficientcontrast cannot be imparted to an image observed by an observer in acase where an environment around the image display device is very brightor according to some contents of a displayed image.

The light control device may be disposed on the second surface side ofthe light guide plate. The light control device may include, forexample, a first substrate, a second substrate facing the firstsubstrate, a first transparent electrode provided on a surface facingthe first substrate facing the second substrate, a second transparentelectrode provided on a surface facing the second substrate facing thefirst substrate, and a light control layer sandwiched between the firsttransparent electrode and the second transparent electrode. In addition,in this case, for example, the first transparent electrode may include aplurality of band-shaped first transparent electrode segments extendingin a first direction. The second transparent electrode may include aplurality of band-shaped second transparent electrode segments extendingin a second direction different from the first direction. A lightshielding ratio of a portion of the light control device correspondingto an overlap region between the first transparent electrode segmentsand the second transparent electrode segments (minimum unit region inwhich the light shielding ratio of the light control device changes) maybe controlled on the basis of control of voltages applied to the firsttransparent electrode segments and the second transparent electrodesegments. That is, the light shielding ratio can be controlled on thebasis of a simple matrix method. The first direction and the seconddirection may be orthogonal to each other, for example.

Alternatively, a thin film transistor (TFT) may be provided in each ofthe minimum unit regions in order to control a light shielding ratio ofthe minimum unit region in which a light shielding ratio of the lightcontrol device changes. That is, the light shielding ratio may becontrolled on the basis of an active matrix method. Alternatively, atleast one of the first transparent electrode and the second transparentelectrode may be a so-called solid electrode (electrode not patterned).

The light guide plate may also serve as the first substrate. With such aconfiguration, it is possible to reduce the weight of the entire displaydevice, and there is no fear to cause a user of the display device tofeel uncomfortable. The second substrate may be thinner than the firstsubstrate. In the light guide device of the first configurationincluding the light control device, the size and the position of aregion of the light control device for actually controlling light aredetermined on the basis of a signal for displaying an image in the imageforming device. The size of the light control device may be the same as,larger than, or smaller than that of the light guide plate. In short,the second deflecting unit (or virtual image forming region) only needsto be located in an orthogonally projected image of the light controldevice.

A maximum light transmittance of the light control device may be 50% ormore, and a minimum light transmittance of the light control device maybe 30% or less. Incidentally, an upper limit value of the maximum lighttransmittance of the light control device may be 99%, and a lower limitvalue of the minimum light transmittance of the light control device maybe 1%. Here, there is a relationship of (light transmittance)=1−(lightshielding ratio).

The light control device may include an optical shutter in which a lighttransmission control material layer includes a liquid crystal materiallayer. Alternatively, the light control device may include an opticalshutter in which a light transmission control material layer includes aninorganic electroluminescence material layer. However, the light controldevice is not limited thereto. In addition, the light control device mayinclude an optical shutter including an electrophoretic dispersionliquid including many charged electrophoretic particles and a dispersionmedium having a color different from that of the electrophoreticparticles, an optical shutter using an electrodeposition method(electrodeposition·electric field deposition) applying anelectrodeposition/dissociation phenomenon generated by a reversibleoxidation-reduction reaction of metal (for example, a silver particle),an optical shutter applying a color change of a substance generated byan oxidation-reduction reaction of an electrochromic material, or anoptical shutter for controlling a light transmittance by anelectrowetting phenomenon.

Here, in a case where the light control device includes an opticalshutter in which a light transmission control material layer includes aliquid crystal material layer, a material constituting the lighttransmission control material layer is not limited, but examples thereofinclude a twisted nematic (TN) type liquid crystal material and a supertwisted nematic (STN) type liquid crystal material. In addition, in acase where the light control device includes an optical shutter in whicha light transmission control material layer includes an inorganicelectroluminescence material layer, a material constituting the lighttransmission control material layer is not limited, but examples thereofinclude tungsten oxide (WO₃).

Specific examples of a material constituting the first substrate and thesecond substrate in the light control device include a transparent glasssubstrate such as a soda lime glass or a white plate glass, a plasticsubstrate, a plastic sheet, and a plastic film. Here, examples of theplastic include polyethylene terephthalate, polyethylene naphthalate,polycarbonate, a cellulose ester such as cellulose acetate, afluorocarbon polymer such as polyvinylidene fluoride or a copolymer ofpolytetrafluoroethylene and hexafluoropropylene, a polyether such aspolyoxymethylene, polyacetal, polystyrene, a polyolefin such aspolyethylene, polypropylene, or methylpentene polymer, a polyimide suchas polyamideimide or polyetherimide, polyamide, polyether sulfone,polyphenylene sulfide, tetraacetyl cellulose, brominated phenoxy,polyarylate, and polysulfone. The plastic sheet and the plastic film mayhave rigidity that does not easily bend or may have flexibility. In acase where each of the first substrate and the second substrate includesa transparent plastic substrate, a barrier layer including an inorganicmaterial or an organic material may be formed on an inner surface of thesubstrate.

Examples of the first transparent electrode and the second transparentelectrode include a so-called transparent electrode. Specific examplesthereof include an indium-tin composite oxide (indium tin oxide (ITO),including Sn-doped In₂O₃, crystalline ITO, and amorphous ITO),fluorine-doped SnO₂ (FTO), F-doped In₂O₃ (IFO), antimony-doped SnO₂(ATO), SnO₂, ZnO (including Al-doped ZnO and B-doped ZnO), indium-zinccomposite oxide (indium zinc oxide (IZO)), a spinel type oxide, an oxidehaving a YbFe₂O₄ structure, and a conductive polymer such aspolyaniline, polypyrrole, or polythiophene, but are not limited thereto.In addition, two or more kinds thereof can be used in combination. Thefirst transparent electrode and the second transparent electrode can beformed on the basis of a physical vapor deposition method (PVD method)such as a vacuum vapor deposition method or a sputtering method, variouschemical vapor deposition methods (CVD methods), various kinds ofcoating, and the like. Basically, patterning of an electrode isunnecessary. However, in a case of patterning as desired, patterning canbe performed by an arbitrary method such as an etching method, alift-off method, or a method using various masks.

The first substrate and the second substrate are sealed with a sealingmember to be bonded to each other at an outer edge portion. Examples ofthe sealing agent also referred to as a seal agent include variousresins including a thermosetting resin, a photocurable resin, amoisture-curable resin, and an anaerobic curing resin, such as an epoxyresin, a urethane-based resin, an acrylic resin, a vinyl acetate-basedresin, an ene-thiol-based resin, a silicone-based resin, or a modifiedpolymer resin.

In some cases, light passing through the light control device can becolored to a desired color by the light control device. In addition, inthis case, a color to which light is colored by the light control devicemay be variable or fixed. In the former case, for example, it is onlyrequired to laminate a light control device colored in red, a lightcontrol device colored in green, and a light control device colored inblue. In addition, in the latter case, a color to which light is coloredby the light control device is not limited, but may be brown, forexample.

Furthermore, in some cases, the light control device may be detachablydisposed. In order to detachably dispose the light control device, forexample, the light control device may be attached, for example, to aframe using a screw manufactured from a transparent plastic.Alternatively, the light control device may be attached to a frame byforming a groove in the frame and engaging the light control device withthe groove or by attaching a magnet to the frame. Alternatively, thelight control device may be fitted in a slide portion by forming theslide portion in a frame. In addition, it is only required to attach aconnector to the light control device, and to electrically connect thelight control device to a control circuit (for example, included in acontrol device for controlling an image forming device) for controllinga light shielding ratio (light transmittance) of the light controldevice via the connector or wiring. The light control device may becurved.

The light shielding member and/or the light control device describedabove can also be appropriately applied to the light guide device of thesecond configuration.

The display device of the present disclosure including the light controldevice may further include an environmental illuminance measuring sensorfor measuring illuminance of an environment in which the display deviceis placed, and may control a light shielding ratio of the light controldevice on the basis of a measurement result of the environmentalilluminance measuring sensor. Alternatively, the display device mayfurther include an environmental illuminance measuring sensor formeasuring illuminance of an environment in which the display device isplaced, and may control brightness of an image formed by the imageforming device on the basis of a measurement result of the environmentalilluminance measuring sensor. These forms may be combined with eachother.

Alternatively, the display device of the present disclosure includingthe light control device may further include a transmitted lightilluminance measuring sensor for measuring illuminance based on lightwhich has passed through the light control device from an externalenvironment, and may control a light shielding ratio of the lightcontrol device on the basis of a measurement result of the transmittedlight illuminance measuring sensor. Alternatively, the display devicemay further include a transmitted light illuminance measuring sensor formeasuring illuminance based on light which has passed through the lightcontrol device from an external environment, and may control brightnessof an image formed by the image forming device on the basis of ameasurement result of the transmitted light illuminance measuringsensor. Note that the transmitted light illuminance measuring sensor isdesirably disposed closer to an observer than the light guide plate. Atleast two transmitted light illuminance measuring sensors may bedisposed, and illuminance based on light which has passed through aportion with a high light shielding ratio and illuminance based on lightwhich has passed through a portion with a low light shielding ratio maybe measured. These forms may be combined with each other. Furthermore,these forms may be combined with the above-described form in whichcontrol is performed on the basis of a measurement result of theenvironmental illuminance measuring sensor.

As described above, if a transmittance of the light control device iscontrolled on the basis of a measurement result of the environmentalilluminance measuring sensor, brightness of an image formed by the imageforming device is controlled on the basis of a measurement result of theenvironmental illuminance measuring sensor, a transmittance of the lightcontrol device is controlled on the basis of a measurement result of thetransmitted light illuminance measuring sensor, and brightness of animage formed by the image forming device is controlled on the basis of ameasurement result of the transmitted light illuminance measuringsensor, it is possible not only to impart a high contrast to an imageobserved by an observer but also to optimize an observation state of animage depending on illuminance of an environment around the displaydevice. The illuminance sensor (environmental illuminance measuringsensor or transmitted light illuminance measuring sensor) only needs tobe constituted by a well-known illuminance sensor, and only needs to becontrolled on the basis of a well-known control circuit.

When a measurement result of the environmental illuminance measuringsensor becomes a predetermined value (also referred to as “firstilluminance measurement value” for convenience) or more, a lighttransmittance of the light control device may be set to a predeterminedvalue (also referred to as a “first light transmittance” forconvenience) or less. Alternatively, when a measurement result of theenvironmental illuminance measuring sensor becomes a predetermined value(also referred to as “second illuminance measurement value” forconvenience) or less, a light transmittance of the light control devicemay be set to a predetermined value (also referred to as a “second lighttransmittance” for convenience) or more. Furthermore, in view ofilluminance of the environmental illuminance measuring sensor, in a casewhere a measurement result of the transmitted light illuminancemeasuring sensor is not desired illuminance, or in a case where evenmore delicate illumination adjustment is desired, it is only required toadjust a light transmittance of the light control device while a valueof the transmitted light illuminance measuring sensor is monitored.Here, the first illuminance measurement value may be 10 lux, and thefirst light transmittance may be any value of 1% to 30%, the secondilluminance measurement value may be 0.01 lux, and the second lighttransmittance may be any value of 51% to 99%. In addition, in a casewhere an illuminance measurement value of the environmental illuminancemeasuring sensor is 1×10⁻³ lux or less, for example, a driving voltageof the light control device is preferably controlled to shorten drivingtime and to increase a light transmittance of the light control device.

As described above, the light guide device is a semi-transmissive type(see-through type). Specifically, at least a portion of the light guidedevice facing the eyeball (pupil) of an observer is madesemi-transmissive (see-through), and an outside scene can be viewedthrough this portion (and further through a light control device in acase where the light control device is disposed) of the light guidedevice. The display device of the present disclosure may include oneimage display device (single eye type) or two display devices (binoculartype). In a case where a light control device is disposed, in abinocular type, on the basis of a signal for displaying an image, alight transmittance of a part of the light control device may be changedin both image display devices, or a light transmittance of a part of thelight control device may be changed in one of the image display devices.Incidentally, here, the term “semi-transmissive” may be used, and theterm “semi-transmissive” does not mean that a half (50%) of incidentlight is transmitted or reflected, but means that a part of incidentlight is transmitted and the remaining light is reflected.

The frame includes a front portion disposed in front of an observer andtwo temple portions rotatably attached to both ends of the front portionvia hinges. Note that a modern portion is attached to a distal endportion of each of the temple portions. The front portion may have arim. The image display device is attached to the frame. Specifically,for example, it is only required to attach the image forming device tothe temple portions. In addition, the front portion and the two templeportions may be integrally formed. That is, when the entire displaydevice of the present disclosure is viewed, the frame has substantiallythe same structure as ordinary eyeglasses. A material constituting theframe including a pad portion may be the same material as a materialconstituting ordinary eyeglasses, such as metal, alloy, plastic, or acombination thereof. Furthermore, a nose pad may be attached to thefront portion. That is, when the entire display device of the presentdisclosure is viewer, an assembly of the frame (including a rim in somecases) and the nose pad has substantially the same structure as ordinaryeyeglasses. The nose pad may also have a well-known configuration andstructure.

In a case where a light control device is disposed, the light controldevice may be disposed in the front portion. In addition, the lightguide device may be attached to the light control device. Incidentally,the light guide device may be attached to the light control device whilebeing in a close contact thereto, or may be attached to the lightcontrol device with a gap therebetween. In addition, the light controldevice may be fitted in a rim. Alternatively, at least one of the firstsubstrate and the second substrate may be attached to the frame, forexample. However, the present disclosure is not limited thereto. From anobserver side, the light guide device and the light control device maybe disposed in this order, or the light control device and the lightguide device may be disposed in this order.

Wiring (signal line, power supply line, or the like) from one or twoimage forming devices desirably extends from a distal end portion of amodern portion to an outside via a temple portion and an inside of themodern portion to be connected to a control device (control circuit orcontrol means) from a viewpoint of design of the display device or easeof mounting. Furthermore, more desirably, each image forming deviceincludes a headphone portion, and headphone portion wiring from eachimage forming device extends from a distal end of the modern portion tothe headphone portion via the temple portion and an inside of the modernportion. Examples of the headphone portion include an inner ear typeheadphone portion and a canal type headphone portion. More specifically,the headphone portion wiring preferably extends from a distal endportion of the modern portion to the headphone portion so as to goaround a back side of the auricle (auditory capsule). In addition, animaging device may be attached to the central portion of the frontportion. Specifically, the imaging device includes, for example, asolid-state imaging element including a CCD or CMOS sensor and a lens.Wiring from the imaging device only needs to be connected to one of theimage display devices (or the image forming devices), for example, viathe front portion. Furthermore, the wiring only needs to be included inwiring extending from the image display device (or the image formingdevice). The imaging device may be attached to the central portion or anend portion of the frame or may be attached to the temple portion.

Alternatively, in a case where the display device of the presentdisclosure is a binocular type, a light guide plate may be disposed on acentral side of the face of an observer with respect to an image formingdevice as a whole. The display device may further include a connectingmember to connect two image display devices to each other. Theconnecting member may be attached to a side facing an observer in acentral portion of a frame located between the two pupils of theobserver. A projected image of the connecting member may be included ina projected image of the frame.

In this way, if a connecting member is attached to a central portion ofa frame located between the two pupils of an observer, that is, if animage display device is not directly attached to the frame, a templeportion expands outward when the observer wears the frame on the head.As a result, even if the frame deforms, due to the deformation of theframe, displacement (position change) of an image forming device or alight guide plate is not generated, or is extremely small even if thedisplacement (position change) is generated. Therefore, it is possibleto reliably prevent a convergence angle of left and right images fromchanging. In addition, there is no need to increase rigidity of a frontportion of the frame. Therefore, an increase in weight of the frame,deterioration of designability, and an increase in cost are not caused.In addition, the image display device is not directly attached to theframe. Therefore, it is possible to freely select design, color, and thelike of the frame according to preference of an observer, there are fewrestrictions on the design of the frame, and the degree of freedom indesign is high. In addition, the connecting member is disposed betweenan observer and the frame, and a projected image of the connectingmember is included in a projected image of the frame. In other words,when the head mounted display is viewed from the front of an observer,the connecting member is concealed by the frame. Therefore, the headmounted display can have a high design property and designcharacteristic.

Note that the connecting member is preferably attached to a side facingan observer in a central portion of the front portion (corresponding toa bridge portion in ordinary eyeglasses) located between the two pupilsof the observer.

The two image display devices are connected by the connecting member.Specifically, the image forming device may be attached to each endportion of the connecting member such that an attachment state can beadjusted. In addition, in this case, each image forming device ispreferably located outside the pupils of an observer. Furthermore, insuch a configuration, if a distance between the center of an attachmentportion of one of the image forming devices and one end portion (oneendpiece, wraparound endpiece) of the frame is represented by α, adistance between the center of the connecting member and one end portion(one endpiece) of the frame is represented by β, a distance between thecenter of an attachment portion of the other image forming device andone end portion (one endpiece) of the frame is represented by γ, and thelength of the frame is represented by L, 0.01×L≤α≤0.30×L is satisfied,0.05×L≤α≤0.25×L and 0.35×L≤β≤0.65×L are preferably satisfied,0.45×L≤β≤0.55×L and 0.70×L≤γ≤0.99×L are preferably satisfied, and0.75×L≤γ≤0.95×L is preferably satisfied. In attachment of the imageforming device to each end portion of the connecting member,specifically, for example, through holes are formed at three endportions of the connecting member, screwing portions corresponding tothe through holes are formed on the image forming device, and screws arecaused to pass through the through holes to be screwed into the screwingportions formed in the image forming device. A spring is insertedbetween each of the screws and each of the screwing portions. In thisway, an attachment state of the image forming device (inclination of theimage forming device with respect to the connecting member) can beadjusted according to a fastening state of the screws.

Here, the center of the attachment portion of the image forming devicerefers to a bisecting point of a portion where a projected image of theimage forming device obtained by projecting the image forming device andthe frame onto a virtual plane overlaps with a projected image of theframe in an axial direction of the frame while the image forming deviceis attached to the connecting member. In addition, the center of theconnecting member refers to a bisecting point of a portion where theconnecting member is in contact with the frame in the axial direction ofthe frame while the connecting member is attached to the frame. Thelength of the frame is the length of a projected image of the frame in acase where the frame is curved. Note that a projection direction isassumed to be a direction perpendicular to the face of an observer.

Alternatively, specifically, the connecting member may connect the twolight guide plates to each other although the two image display devicesare connected to each other by the connecting member. Note that there isa case where the two light guide plates are integrally manufactured. Insuch a case, the connecting member is attached to the integrallymanufactured light guide plates. However, such a form is also includedin a form in which the connecting member connects the two light guideplates to each other. If a distance between the center of one of theimage forming devices and one end portion of the frame is represented byα40 and a distance between the center of the other image forming deviceand one end portion of the frame is represented by γ′, values of α′ andγ′ are desirably set to similar values to the above values α and γ. Notethat the center of the image forming device refers to a bisecting pointof a portion where a projected image of the image forming deviceobtained by projecting the image forming device and the frame onto avirtual plane overlaps with a projected image of the frame in an axialdirection of the frame while the image forming device is attached to thelight guide plate.

The shape of the connecting member is essentially arbitrary as long as aprojected image of the connecting member is included in a projectedimage of the frame, and examples thereof include a bar shape or anelongated plate shape. Examples of a material constituting theconnecting member include metal, alloy, plastic, and a combinationthereof.

The display device of the present disclosure can receive a signal fordisplaying an image in the image display device (a signal for forming avirtual image in the light guide device) from an outside. In such aform, information and data regarding an image displayed on the imagedisplay device is recorded, kept, and stored, for example, in aso-called cloud computer or a server. By inclusion of a communicationunit such as a mobile phone or a smartphone in the display device or bycombination of the display device and a communication unit, variouskinds of information and data can be transmitted and exchanged betweenthe cloud computer or the server and the display device, and a signalbased on various kinds of information and data, that is, a signal fordisplaying an image in the image display device (a signal for forming avirtual image in the light guide device) can be received. Alternatively,a signal for displaying an image in the image display device (a signalfor forming a virtual image in the light guide device) may be stored inthe display device. Note that an image displayed on the image displaydevice includes various kinds of information and various kinds of data.Alternatively, the display device may include an imaging device. Animage imaged by the imaging device may be sent to a cloud computer or aserver via a communication unit. The cloud computer or the server mayretrieve various kinds of information and data corresponding to theimage imaged by the imaging device. The various kinds of retrievedinformation and data may be sent to the display device via thecommunication unit, and may be displayed on the image display device.

When the image imaged by the imaging device is sent to the cloudcomputer or the server via the communication unit, the image imaged bythe imaging device may be displayed on the image display device to beconfirmed by the light guide device. Specifically, an outer edge of aspace region imaged by the imaging device may be displayed in a frameshape in the light control device. Alternatively, the light shieldingratio of a region of the light control device corresponding to the spaceregion imaged by the imaging device may be higher than the lightshielding ratio of a region of the light control device corresponding toan outside of the space region imaged by the imaging device. In such aform, an observer sees the space region imaged by the imaging devicedarker than an outside of the space region imaged by the imaging device.Alternatively, the light shielding ratio of a region of the lightcontrol device corresponding to the space region imaged by the imagingdevice may be lower than the light shielding ratio of a region of thelight control device corresponding to an outside of the space regionimaged by the imaging device. In such a form, an observer sees the spaceregion imaged by the imaging device brighter than an outside of thespace region imaged by the imaging device. In addition, this makes itpossible for an observer to easily and reliably recognize a position inan outside to be imaged by the imaging device.

A position in a region of the light control device corresponding to thespace region captured by the imaging device is preferably calibrated.Specifically, for example, by inclusion of a mobile phone or asmartphone in the display device or by combination of the display devicewith a mobile phone, a smartphone, or a personal computer, in a mobilephone, a smartphone, or a personal computer, the mobile phone, thesmartphone, or the personal computer can display a space region imagedby the imaging device. In addition in a case where there is a differencebetween the space region displayed on the mobile phone, the smartphone,or the personal computer and a region of the light control devicecorresponding to a space region imaged by the imaging device, bymoving/rotating/swiveling or enlarging/reducing a region of the lightcontrol device corresponding to a space region imaged by the imagingdevice using a control circuit (which can be substituted by a mobilephone, a smartphone, or a personal computer) for controlling a lightshielding ratio (light transmittance) of the light control device, it isonly required to eliminate the difference between the space regiondisplayed on the mobile phone, the smartphone, or the personal computerand the region of the light control device corresponding to a spaceregion imaged by the imaging device.

The display device of the present disclosure including theabove-described various modified examples can be used, for example, forreceiving/displaying an electronic mail; displaying various kinds ofinformation or the like in various sites on the Internet; display ofvarious explanations, for example, for driving, operating, maintaining,or disassembling an observation object such as various devices, asymbol, a sign, a mark, an emblem, a design, or the like; display ofvarious explanations concerning an observation object such as a personor an article, a symbol, a sign, a mark, an emblem, a design, or thelike; display of a moving image and a still image; display of subtitlesof a movie and the like; display of descriptive text concerning videosynchronized with video and closed caption; display of variousexplanations concerning an observation object in play and kabuki, Noh,Kyogen, opera, concert, ballet, various dramas, an amusement park, amuseum, a sightseeing spot, a holiday destination, tourist information,and the like, and descriptive text for explaining contents thereof,progress status thereof, backgrounds thereof, and the like; and displayof closed caption. In play and kabuki, Noh, Kyogen, opera, concert,ballet, various dramas, an amusement park, a museum, a sightseeing spot,a holiday destination, tourist information, and the like, it is onlyrequired to display characters as an image relating to an observationobject on the display device at an appropriate timing. Specifically, forexample, in accordance with progress status of a movie or the like, orin accordance with progress status of a play or the like, an imagecontrol signal is sent to the display device, and an image is displayedon the display device on the basis of a predetermined schedule or timeallocation by operation of an operator or under control of a computer orthe like. In addition, various kinds of explanations concerning anobservation object such as various devices, a person, or an article aredisplayed. If the imaging device photographs (images) an observationobject such as various devices, a person, or an article, and the displaydevice analyzes the photographed (imaged) contents, the display devicecan display previously-created various explanations concerning anobservation object such as various devices, a person, or an article.

An image signal to the image forming device may include not only animage signal (for example, character data) but also, for example,brightness data (brightness information) concerning an image to bedisplayed, chromaticity data (chromaticity information), or brightnessdata and chromaticity data. The brightness data may correspond tobrightness of a predetermined region including an observation objectviewed through the light guide device. The chromaticity data maycorrespond to chromaticity of a predetermined region including anobservation object viewed through the light guide device. In this way,by inclusion of brightness data concerning an image, brightness(lightness) of an image displayed can be controlled. By inclusion ofchromaticity data concerning an image, chromaticity (color) of an imagedisplayed can be controlled. By inclusion of brightness data andchromaticity data concerning an image, brightness (lightness) andchromaticity (color) of an image displayed can be controlled. In a casewhere brightness data corresponds to brightness of a predeterminedregion including an observation object viewed through the image displaydevice, it is only required to set a value of brightness data such thatthe higher a value of brightness of a predetermined region including anobservation object viewed through the image display device is, thehigher a value of brightness of an image is (that is, the brighter animage is displayed). In addition, in a case where chromaticity datacorresponds to chromaticity of a predetermined region including anobservation object viewed through the image display device, it is onlyrequired to set a value of chromaticity data such that chromaticity of apredetermined region including an observation object viewed through theimage display device has a roughly complementary color relationship withchromaticity of an image to be displayed. A complementary color refersto a combination of colors diametrically opposed to each other in acolor circle. The complementary color also means a complementary color,for example, green for red, violet for yellow, and orange for blue. Thecomplementary color also means a color to cause a decrease in colorsaturation by mixing a certain color with another color at anappropriate ratio, for example, white in a case of light and black in acase of an object. However, a complementary property in visual effectsin parallel disposition is different from a complementary property inmixing. The complementary color is also referred to as a surplus color,a control color, or an opposite color. However, the opposite colordirectly indicates a color opposite to a complementary color, whereas arange indicated by the complementary color is slightly wide. A colorcombination of complementary colors has a synergistic effect forbringing mutual colors into prominence, and this is referred to ascomplementary color harmony.

EXAMPLE 1

Example 1 relates to the display device of the present disclosure andthe method for manufacturing a light emitting element of the presentdisclosure. FIGS. 1, 2, 3, 4, 5, and 6 illustrate schematic partialcross-sectional views of a light emitting element constituting theoptical device of the present disclosure and the display device of thepresent disclosure, and a light emitting element obtained by the methodfor manufacturing a light emitting element of the present disclosure.FIG. 7 illustrates a schematic partial plan view of a light emittingelement as viewed from a lens system side. FIG. 8 illustrates aschematic cross-sectional view of a light emitting element along anarrow A-A in FIG. 1 or the like. FIG. 9 illustrates a schematic partialplan view of a light emitting element as viewed from the opposite sideto the lens system side. Furthermore, FIG. 10 illustrates a conceptualdiagram of an image forming device of Example 1. FIG. 11 illustrates aschematic view of the display device (specifically, head mounted display(HMD)) of Example 1 as viewed from above. FIG. 12 illustrates aschematic view of the display device of Example 1 as viewed from thefront. FIG. 13A illustrates a schematic view of the display device ofExample 1 as viewed from a side. FIG. 13B schematically illustrates apropagation state of light in a light guide plate constituting an imagedisplay device. FIG. 13C illustrates a schematic cross-sectional viewillustrating a part of a reflection type volume hologram diffractiongrating in an enlarged manner. In FIG. 7, the antireflection layercovers a top surface of a separation groove. In order to clearlyillustrate a formation position of the separation groove, the separationgroove is illustrated.

More specifically, the display device of Example 1 or any one ofExamples 2 to 8 described later is a head mounted display (HMD), andincludes (a) a frame 10 attached to the head of an observer 20 (forexample, eyeglass-type frame 10), and (b) an image display device 100A,100B, 200A, or 200B attached to the frame 10. Incidentally, the displaydevice of Example 1 or any one of Examples 2 to 8 described later isspecifically a binocular type including two image display devices, butmay be a single eye type including one image display device. Forexample, an image forming device 111 displays a color image. Inaddition, the image display device 100A, 100B, 200A, or 200B in Example1 or any one of Examples 2 to 8 described later includes (A) the imageforming device 111, (B) light guide device 120, 130, 220, or 230 forguiding an image from the image forming device 111 to a pupil 21 of theobserver 20, and (C) a lens system 114 for making an image from theimage forming device 111 incident on the light guide device 120, 130,220, or 230. The image forming device 111 includes light emittingelements 300 arranged in a two-dimensional matrix. The light emittingelements 300 will be described in detail later.

The light guide device 120 in the display device of Example 1 is thelight guide device of the first configuration, more specifically, thelight guide device of the first-A configuration. That is, the lightguide device 120 in the display device of Example 1 includes a lightguide plate 121, a first deflecting unit 122, and a second deflectingunit 123. Light which has been emitted from the image forming device 111and has passed through the lens system 114 is incident on the firstdeflecting unit 122. Then, the light deflected by the first deflectingunit 122 repeats total reflection inside the light guide plate 121, isdeflected by the second deflecting unit 123, is emitted from the lightguide plate 121, and reaches the pupil 21 of the observer 20. A surfaceof the light guide plate 121 facing the lens system 114 is referred toas a first surface 121A, and a surface facing the first surface 121A isreferred to as a second surface 121B. The first deflecting unit 122 andthe second deflecting unit 123 are disposed on (more specifically,bonded to) the second surface 121 B of the light guide plate 121.However, the present disclosure is not limited to such a disposition.The first surface 121A constitutes a light guide plate incidence surfaceand a light guide plate emission surface. The observer 20 faces thefirst surface 121A of the light guide plate 121.

More specifically, the light guide device 120 in Example 1 includes thefirst deflecting unit 122 for deflecting light incident from the lenssystem 114, the light guide plate 121 for propagating the lightdeflected by the first deflecting unit 122 by total reflection therein,and the second deflecting unit 123 for deflecting and emitting the lightpropagated by total reflection inside the light guide plate 121. Thelight guide plate 121 is disposed so as to face the image forming device111 with the lens system 114 interposed therebetween. In the lens system114, the light emitted from the image forming device 111 is convertedinto a parallel light beam and is made incident on the light guidedevice 120.

A (X, Y, Z) orthogonal coordinate system is assumed. In addition, apoint where a central light beam CL which is a light beam which has beenemitted from the center of the image forming device 111 and has passedthrough a node of the lens system 114 on the image forming device side(that is, a light beam emitted from the center of the image formingdevice 111 in a normal direction of the image forming device 111) isincident on the light guide plate 121 or 131 is referred to as a lightguide plate center point O. In addition, an axis passing through thelight guide plate center point O and being parallel to an axialdirection of the light guide plate 121 or 131 (a direction in whichlight is propagated through the light guide plate 121 or 131) isreferred to as an X axis. An axis passing through the light guide platecenter point O and coinciding with a normal line of the light guideplate 121 or 131 is referred to as a Y axis. A Z axis passes through thelight guide plate center point O and extends in a height direction ofthe light guide plate 121 or 131. The center point of the firstdeflecting unit 122 or 132 is the light guide plate center point O. Thatis, as illustrated in FIG. 13B, in the image display device 100A or100B, the central light beam CL which has been emitted from the centerof the image forming device 111 and has passed through a node of thelens system 114 on the image forming device side collides with the lightguide plate 121 or 131, for example, vertically. In other words, thecentral light beam CL is incident on the light guide plate 121 or 131 atan incident angle of 0 degrees.

In Example 1, each of the first deflecting unit (first diffractiongrating member) 122 and the second deflecting unit (second diffractiongrating member) 123 includes a hologram diffraction grating,specifically, a reflection type hologram diffraction grating, morespecifically, a reflection type volume hologram diffraction grating, anddiffracts and reflects incident light. The reflection type volumehologram diffraction grating includes, for example, a plurality ofdiffraction grating layers (photopolymer layers). In each diffractiongrating layer including a photopolymer material, an interference fringecorresponding to one type of wavelength band (or wavelength) is formed,and is manufactured by a conventional method. A pitch of theinterference fringe 122 a or 123 a formed in the diffraction gratinglayer (diffraction grating member) is constant, and the interferencefringe is linear and parallel to the Z direction of the light guideplate. Note that FIGS. 10, 18, 21, and 22 illustrate one diffractiongrating layer for simplification of the drawings.

As illustrated in the enlarged schematic partial cross-sectional view ofthe reflection type volume hologram diffraction grating in FIG. 13C, aninterference fringe having an inclination angle (slant angle) φ isformed in the reflection type volume hologram diffraction grating. Here,the inclination angle φ refers to an angle formed by a surface of thereflection type volume hologram diffraction grating and an interferencefringe. The interference fringe is formed from an inside to a surface ofthe reflection type volume hologram diffraction grating. Theinterference fringe satisfies Bragg condition. Here, the Bragg conditionmeans a condition satisfying the following formula (A). In formula (A),m represents a positive integer, λ represents a wavelength, d representsa pitch of a lattice plane (an interval in a normal direction of avirtual plane including an interference fringe), and θ represents acomplementary angle of an angle incident on the interference fringe. Inaddition, a relationship among θ, an inclination angle φ, and anincident angle Ψ in a case where light enters a diffraction gratingmember at the incident angle Ψ is as illustrated in formula (B).Furthermore, a pitch ∧ of an interference fringe on a surface of adiffraction grating member is as illustrated in formula (C).

m·λ=2·d·sin (θ)   (A)

θ=90°−(φ+Ψ)   (B)

∧=d/sin (φ)   (C)

The image display device 100A, 100B, 200A, or 200B may be attached tothe frame 10 fixedly or detachably. The light guide devices 120 and 130are semi-transmissive (see-through). Specifically, at least portions ofa light guide device facing both eyes of the observer 20 (morespecifically, the light guide plate 121 or 131 and the second deflectingunit 123 or 133) are semi-transmissive (see-through).

In Example 1, the image forming device 111 includes a plurality of (forexample, 640×480) pixels arranged in a two-dimensional matrix. Each ofthe pixels is constituted by the light emitting element 300 describedlater. The entire image forming device 111 is housed in a casing 115(indicated by the one dot chain line in FIG. 10). The lens system 114includes, for example, a convex lens, and generates parallel light.Light emitted from the light emitting element 300 constituting the imageforming device 111 is incident on the lens system (parallel lightemitting optical system, collimating optical system) 114, and the lightis emitted as parallel light from the lens system 114.

The frame 10 includes a front portion 11 disposed in front of theobserver 20, two temple portions 13 rotatably attached to both ends ofthe front portion 11 via hinges 12, and a modern portion (also referredto as a leading cell, an earmuff, or an ear pad) 14 attached to a distalend portion of each of the temple portions 13. In addition, a nose pad10′ is attached. That is, basically, an assembly of the frame 10 and thenose pad 10′ has substantially the same structure as ordinaryeyeglasses. Furthermore, each casing 115 is detachably attached to thetemple portion 13 by an attachment member 19. The frame 10 ismanufactured from metal or plastic. Note that each casing 115 may beattached to the temple portion 13 by the attachment member 19 so as notto be detachable. In addition, for an observer owing and wearingeyeglasses, each casing 115 may be detachably attached to the templeportion 13 of the frame 10 of the eyeglasses owned by the observer bythe attachment member 19. Each casing 115 may be attached to an outsideor an inside of the temple portion 13. Alternatively, the light guideplate 121 may be fitted in a rim included in the front portion 11.

Furthermore, wiring (signal line, power supply line, or the like) 15extending from one of the image forming devices 111 extends to anoutside from a distal end portion of the modern portion 14 via thetemple portion 13 and an inside of the modern portion 14, and isconnected to a control device (control circuit or control unit) 18.Furthermore, the image forming device 111 includes a headphone portion16. Headphone portion wiring 16′ extending from the image forming device111 extends from a distal end portion of the modern portion 14 to theheadphone portion 16 via the temple portion 13 and an inside of themodern portion 14. More specifically, the headphone portion wiring 16′extends from a distal end portion of the modern portion 14 to theheadphone portion 16 so as to go around a back side of the auricle(auditory capsule). With such a configuration, an impression that theheadphone portion 16 or the headphone portion wiring 16′ is disorderedlydisposed is not given, and a simple display device can be obtained. Asdescribed above, the wiring (signal line, power supply line, or thelike) 15 is connected to the control device (control circuit) 18. Thecontrol device 18 includes, for example, an image information storagedevice 18A. In addition, the control device 18 performs processing forimage display. Each of the control device 18 and the image informationstorage device 18A may include a well-known circuit.

An imaging device 17 including a solid-state imaging element including aCCD or CMOS sensor and a lens (these are not illustrated) as necessaryis attached to a central portion 11′ of the front portion 11 with asuitable attachment member (not illustrated). A signal from the imagingdevice 17 is sent to the control device (control circuit) 18 via wiring(not illustrated) extending from the imaging device 17.

Hereinafter, the light emitting element 300 in the image forming device111 constituting the display device of Example 1 will be described.

The light emitting element 300 includes a laminated structure 301including at least one layer of a light emitting laminate including afirst electrode (n-side electrode), a second electrode (p-sideelectrode), and a light emitting layer provided between the firstelectrode and the second electrode. In the laminated structure 301, athrough hole 360 formed in a lamination direction of the laminatedstructure 301 for emitting light from the light emitting layer towardthe lens system 114 is formed. An antireflection layer (light absorbinglayer) 370 is formed in a portion of the laminated structure 301 facingthe lens system 114. One light emitting element 300 has a plurality ofthrough holes 360 formed. In addition, the light emitting elements 300are electrically and optically separated from each other by a separationgroove 380, and have a structure in which optical crosstalk hardlyoccurs.

Here, the antireflection layer 370 is formed up to an edge portion ofthe through hole 360 in the laminated structure 301. That is, when thelight emitting element 300 is viewed from a lens system side, topsurfaces of the antireflection layer 370 and the through hole 360 arevisually recognized. In other words, when the light emitting element 300is viewed from the lens system 114, the top surfaces of theantireflection layer 370 and the through hole 360 are visuallyrecognized, and a top surface of the laminated structure 301 is notvisually recognized. Specifically, the antireflection layer 370 includesmetal oxide (for example, chromium oxide).

The through hole 360 includes, for example, a core portion 361 and aclad layer 362 disposed between the laminated structure 301 and the coreportion 361. The core portion 361 is filled, for example, with air or adielectric material such as SiO₂, SiN, or Ta₂O₅. Meanwhile, the cladlayer 362 includes, for example, an outer clad layer (layer in contactwith the laminated structure 301) including an insulating material suchas SiO₂ and an inner clad layer (layer facing the core portion 361)including a light-reflecting metal such as aluminum (Al), silver (Ag),or gold (Au). Specifically, for example, the core portion 361 includesSiN, the inner clad layer (layer facing the core portion 361) includes asilver (Ag) layer having a thickness of 50 nm, and the outer clad layer(layer in contact with the laminated structure 301) includes SiO₂.However, the configuration and structure of the through hole 360 are notlimited to the above-described configuration and structure.

In addition, the light emitting element 300 has a laminated structure301 including three layers of a light emitting laminate that emits redlight (first light emitting laminate) 310, a light emitting laminatethat emits green light (second light emitting laminate) 320, and a lightemitting laminate that emits blue light (third light emitting laminate)330.

Furthermore, the image forming device 111 includes a circuit board 390in which a light emitting element driving circuit (not illustrated) isprovided, and each light emitting element 300 is connected to the lightemitting element driving circuit provided on the circuit board 390. Inaddition, the image forming device 111 further includes a supportsubstrate 351 constituting the laminated structure 301 on a lightemitting side. In Example 1, more specifically, the antireflection layer370 is formed on a surface (surface facing the lens system 114) 351A (ona top surface) of the support substrate 351. A second support substrate352 is disposed between the third light emitting laminate 330 and thecircuit board 390. The support substrate 351, the second supportsubstrate 352, and the circuit board 390 are each constituted, forexample, by a silicon semiconductor substrate. A light emitting elementdriving circuit constituted by a well-known driving circuit suitable fordriving the light emitting element 300 is connected to the lightemitting element 300, for example, using a bump portion, by a metalbonding method for connecting a contact portion (specifically, formed onthe second support substrate 352) including copper (Cu) and connected tothe light emitting element 300 to a connection portion including copper(Cu) and provided on the circuit board 390, or on the basis of aconnection method using TCV.

The light emitting laminates 310, 320, and 330 including the firstelectrodes (n-side electrodes) 312A, 322A, and 332A, the secondelectrodes (p-side electrodes) 312B, 322B, and 332B, and the lightemitting layers 311, 321, and 331 provided between the first electrodes312A, 322A, and 332A and the second electrodes 312B, 322B, and 332B havewell-known laminated structures themselves. The light emitting layer hasa structure obtained by laminating a plurality of compound semiconductorlayers, that is, a structure obtained by laminating a first compoundsemiconductor layer, an active layer, and a second compoundsemiconductor layer.

For example, the light emitting layer 311 constituting the lightemitting laminate (first light emitting laminate) 310 that emits redlight has a layer configuration including a buffer layer includingn-type GaAs and a first compound semiconductor layer (for example,including a first clad layer including n-type AlGaAs)/active layerincluding GaAs, AlGaAs, or AlGaInP/second compound semiconductor layer(for example, including a second clad layer including p-type AlGaAs anda cap layer including p-type GaAs). However, the layer configuration isnot limited to such a layer configuration. In addition, for example, thelight emitting layer 321 or 331 constituting the light emitting laminate(second light emitting laminate or third light emitting laminate) 320 or330 that emits green or blue light has a layer configuration including afirst compound semiconductor layer (for example, including an n-typeAlGaN clad layer and an n-type GaN clad layer)/InGaN quantum well activelayer/second compound semiconductor layer (for example, including anon-doped InGaN light guide layer, a p-type AlGaN electron barrierlayer, a p-type GaN/AlGaN superlattice clad layer, and a p-type GaNcontact layer). However, the layer configuration is not limited to sucha layer configuration. Films of various compound semiconductor layersconstituting the light emitting layer can be formed, for example, on thebasis of a MOCVD method.

Hereinafter, a method for manufacturing the light emitting element 300including the laminated structure 301 will be described.

[Step-100]

First, the laminated structure 301 including at least one layer (threelayers in Example 1) of the light emitting laminates 310, 320, and 330including the first electrodes 312A, 322A, and 332A, the secondelectrodes 312B, 322B, and 332B, and the light emitting layers 311, 321,and 331 provided between the first electrodes 312A, 322A, and 332A andthe second electrodes 312B, 322B, and 332B is formed.

Specifically, in advance, the first light emitting laminate 310 isformed on the first light emitting laminate manufacturing substrateexcept for the first electrode 312A, the second light emitting laminate320 is formed on the second light emitting laminate manufacturingsubstrate except for the first electrode 322A, and the third lightemitting laminate 330 is formed on the third light emitting laminatemanufacturing substrate except for the first electrode 332A.

More specifically, the light emitting layer 311 is formed on the firstlight emitting laminate manufacturing substrate on the basis of awell-known MOCVD method, and the second electrode 312E is formed on thelight emitting layer 311, and is patterned into a desired shape. Inaddition, the light emitting layer 321 is formed on the second lightemitting laminate manufacturing substrate on the basis of a well-knownMOCVD method, and the second electrode 322B is formed on the lightemitting layer 321, and is patterned into a desired shape. Furthermore,the light emitting layer 331 is formed on the third light emittinglaminate manufacturing substrate on the basis of a well-known MOCVDmethod, and the second electrode 332B is formed on the light emittinglayer 331, and is patterned into a desired shape.

Then, the support substrate 351 on which a first insulating layer 341 isformed is prepared. The support substrate 351 is bonded to the secondelectrode 312B via the first insulating layer 341. Thereafter, the firstlight emitting laminate manufacturing substrate is removed on the basisof a well-known method. Then, the first electrode 312A is formed on theexposed light emitting layer 311. The first electrode 312A is patternedinto a desired shape. Thereafter, a second insulating layer 342 isformed on the entire surface. In this way, the first light emittinglaminate 310 can be formed on the support substrate 351.

Subsequently, a first separation groove for separating the lightemitting elements 300 from each other is formed. Specifically, a firstrecess is formed by etching the first light emitting laminate 310 fromthe opposite side to the support substrate 351. Thereafter, the firstrecess is filled with an insulating material by a well-known method toform the first separation groove. Then, a first A₁ connection groove(connection portion, the same applies hereinafter) connected to thefirst electrode 312A and a first B₁ connection groove connected to thesecond electrode 312B are formed in the first separation groove. Thefirst A₁ connection groove and the first B₁ connection groove are filledwith a conductive material.

Subsequently, the first light emitting laminate 310 is bonded to thesecond electrode 322B via the second insulating layer 342. Thereafter,the second light emitting laminate manufacturing substrate is removed onthe basis of a well-known method. Then, the first electrode 322A isformed on the exposed light emitting layer 321. The first electrode 322Ais patterned into a desired shape. Thereafter, a third insulating layer343 is formed on the entire surface. In this way, the second lightemitting laminate 320 can be formed on the first light emitting laminate310.

Subsequently, a second separation groove for separating the lightemitting elements 300 from each other is formed. Specifically, a secondrecess is formed by etching the second light emitting laminate 320 fromthe opposite side to the first light emitting laminate 310. Thereafter,the second recess is filled with an insulating material by a well-knownmethod to form the second separation groove. Then, a second A₂connection groove connected to the first electrode 322A and a second B₂connection groove connected to the second electrode 322B are formed inthe second separation groove. In addition, a first A₂ connection grooveconnected to the first A₁ connection groove and a first B₂ connectiongroove connected to the first B₁ connection groove are formed in thesecond separation groove. These connection grooves are also filled witha conductive material.

Thereafter, the second light emitting laminate 320 is bonded to thesecond electrode 332B via the third insulating layer 343. Thereafter,the third light emitting laminate manufacturing substrate is removed onthe basis of a well-known method. Then, the first electrode 332A isformed on the exposed light emitting layer 331. The first electrode 332Ais patterned into a desired shape. Thereafter, a fourth insulating layer344 is formed on the entire surface. In this way, the third lightemitting laminate 330 can be formed on the second light emittinglaminate 320.

Subsequently, a third separation groove for separating the lightemitting elements 300 from each other is formed. Specifically, a thirdrecess is formed by etching the third light emitting laminate 330 fromthe opposite side to the second light emitting laminate 320. Thereafter,the third recess is filled with an insulating material by a well-knownmethod to form the third separation groove. Then, a third A₃ connectiongroove connected to the first electrode 332A and a third B₃ connectiongroove connected to the second electrode 332B are formed in the thirdseparation groove. In addition, a first A₃ connection groove connectedto the first A₂ connection groove, a first B₃ connection grooveconnected to the first B₂ connection groove, a second A₃ connectiongroove connected to the second A₂ connection groove, and a second B₃connection groove connected to the second B₂ connection groove areformed in the third separation groove. These connection grooves are alsofilled with a conductive material.

In this way, the separation groove 380 for separating the light emittingelements 300 from each other is formed, and at the same time, aconnection groove is formed in the separation groove 380. In addition,the laminated structure 301 in which the first light emitting laminate310, the second light emitting laminate 320, and the third lightemitting laminate 330 are laminated can be obtained. The separationgroove 380 is filled with an insulating material having a lowerrefractive index than a compound semiconductor material constituting alight emitting layer, and a connection groove having a light shieldingproperty is formed in a part thereof. Therefore, the light emittingelements 300 are separated from each other not only electrically butalso optically, and a structure in which optical crosstalk hardly occursis formed.

Then, the fourth insulating layer 344 is bonded to the second supportsubstrate 352. Subsequently, in portions of the second support substrate352 located above the first A₃ connection groove, the first B₃connection groove, the second A₃ connection groove, the second B₃connection groove, the third A₃ connection groove, and the third B₃connection groove, connection groove portions reaching these connectiongrooves are formed. Thereafter, a conductive material layer is formed onthe second support substrate 352 including the connection grooveportion, and the conductive material layer on the second supportsubstrate 352 is patterned. In this way, a contact portion including aconductive material layer can be formed on the second support substrate352. A first A contact portion 312 a is electrically connected to thefirst electrode 312A constituting the first light emitting laminate 310via the first A₃ connection groove, the first A₂ connection groove, andthe first A₁ connection groove. A first B contact portion 312 b iselectrically connected to the second electrode 312B constituting thefirst light emitting laminate 310 via the first B₃ connection groove,the first B₂ connection groove, and the first B₁ connection groove. Asecond A contact portion 322 a is electrically connected to the firstelectrode 322A constituting the second light emitting laminate 320 viathe second A₃ connection groove and the second A₂ connection groove. Asecond B contact portion 322 b is electrically connected to the secondelectrode 322B constituting the second light emitting laminate 320 viathe second B₃ connection groove and the second B₂ connection groove. Athird A contact portion 332 a is electrically connected to the firstelectrode 332A constituting the third light emitting laminate 330 viathe third A₃ connection groove. A third B contact portion 332 b iselectrically connected to the second electrode 332B constituting thethird light emitting laminate 330 via the third B₃ connection groove.

Thereafter, a recess reaching the separation groove 380 is formed in thesupport substrate 351 and the first insulating layer 341 on the basis ofan etching method, and the recess is filled with an insulating materialto complete the separation groove 380.

[Step-110]

Next, the antireflection layer (light absorbing layer) 370 is formed onthe laminated structure 301. Specifically, the antireflection layer 370is formed on the surface 351A of the support substrate 351, for example,on the basis of a sputtering method.

[Step-120]

Then, the through hole 360 for emitting light from the light emittinglayers 311, 321, and 331 toward an outside is formed in theantireflection layer 370 and the laminated structure 301 in a laminationdirection of the laminated structure 301, for example, on the basis of aRIE method. A cross-sectional shape obtained by cutting the through hole360 with an imaginary horizontal plane is a circle. The antireflectionlayer 370 is formed up to an edge portion of the through hole 360 in thelaminated structure 301. Subsequently, the clad layer 362 and the coreportion 361 are sequentially formed inside the through hole 360 on thebasis of a well-known method. The clad layer 362 is disposed between thelaminated structure 301 and the core portion 361. Thereafter, if topsurfaces of the antireflection layer 370, the clad layer 362, and thecore portion 361 are polished so as to be flat, it is possible to avoidoccurrence of a problem that emitted light is scattered on a top surfaceof the through hole 360 to reduce efficiency, and this is preferable.

In this way, the light emitting element 300 including the laminatedstructure 301 can be obtained. Incidentally, in a case of forming alaminated structure of a plurality of light emitting laminates (forexample, a first light emitting laminate, a second light emittinglaminate, and a third light emitting laminate), a method forsequentially forming the first light emitting laminate, the second lightemitting laminate, and the third light emitting laminate on a lightemitting laminate manufacturing substrate (corresponding to a supportsubstrate) may be adopted.

[Step-130]

Thereafter, the light emitting element 300 is connected to a lightemitting element driving circuit including a well-known driving circuitsuitable for driving the light emitting element 300 on the basis of awell-known method. In this way, it is possible to obtain the imageforming device 111 constituting the display device of Example 1.

In the display device of Example 1 or an optical device of Example 9described later, an antireflection layer (light absorbing layer) isformed in a portion of the laminated structure facing a lens system. Inaddition, in the method for manufacturing a light emitting element, athrough holes is formed in each of the antireflection layer (lightabsorbing layer) and the laminated structure. Therefore, even when apart of light emitted from the image forming device is reflected by thelens system and is returned to the image forming device, the light isnot reflected by the image forming device, and it is possible toreliably prevent extra light from entering an image observed by anobserver, and it is possible to obtain an image with high image quality.In addition, the light emitting elements are separated from each othernot only electrically but also optically, and have a structure in whichoptical crosstalk hardly occurs. Note that the support substrate isconstituted by a silicon semiconductor substrate. Therefore, in a casewhere the antireflection layer is not formed, occurrence of a phenomenonthat return light is reflected on a surface of an image forming device(support substrate) and is incident on a lens system again issignificant.

EXAMPLE 2

Example 2 is a modification of Example 1, and relates to the light guidedevice of the first-B configuration. As illustrated in the conceptualdiagram of the image forming device in FIG. 14, in Example 2, the firstdeflecting unit 132 reflects light incident on the light guide plate131, and the second deflecting unit 133 transmits, reflects, anddiffracts light propagated by total reflection inside the light guideplate 131 a plurality of times. The first deflecting unit 132 functionsas a reflecting mirror, and the second deflecting unit 133 functions asa semi-transmissive mirror. Specifically, the first deflecting unit 132includes, for example, a metal film (for example, aluminum, Al)containing an alloy, and includes a light reflecting film (a kind ofmirror) for reflecting light incident on the light guide plate 131. Inaddition, the second deflecting unit 133 includes, for example, adielectric multilayer film obtained by laminating many dielectriclaminated films. The dielectric laminated film includes, for example, aTiO₂ film as a high dielectric constant material and a SiO₂ film as alow dielectric constant material. Japanese Translation of PCTInternational Application No. 2005-521099 discloses a dielectricmultilayer film obtained by laminating many dielectric laminated films.The first deflecting unit 132 and the second deflecting unit 133 aredisposed inside the light guide plate 131 (incorporated in the lightguide plate 131). In the drawings, the second deflecting unit 133 isillustrated as a unit including six dielectric laminated films, but isnot limited thereto. A thin piece including the same material as amaterial constituting the light guide plate 131 is sandwiched betweenthe dielectric laminated films. Incidentally, reference numeral 131Aindicates a first surface of the light guide plate 131 facing the lenssystem 114, and reference numeral 131 B indicates a second surfacefacing the first surface 131A.

As for the first deflecting unit 132, by cutting out a portion in whichthe first deflecting unit 132 is provided in the light guide plate 131,a slope to form the first deflecting unit 132 is formed in the lightguide plate 131, a metal film is formed on the slope (for example, themetal film can be formed by a vacuum vapor deposition method), and thenthe cut-out portion of the light guide plate 131 only needs to be bondedto the first deflecting unit 132. In addition, as for the seconddeflecting unit 133, a film of a member obtained by laminating manylayers of the same material (for example, glass) as a materialconstituting the light guide plate 131 and dielectric laminated films isformed, a portion in which the second deflecting unit 133 is provided inthe light guide plate 131 is cut out to form a slope, the member isbonded to the slope, and polishing or the like only needs to beperformed to adjust an outer shape. In this way, the light guide device130 in which the first deflecting unit 132 and the second deflectingunit 133 are provided inside the light guide plate 131 can be obtained.

In Example 2, the image forming device 111 is constituted by a similarimage forming device to that in Example 1. In addition, the light guidedevice 130 has substantially the same configuration and structure asthose of the light guide device 120 of Example 1 except that theconfigurations and structures of the first deflecting unit and thesecond deflecting unit are different.

EXAMPLE 3

Example 3 is also a modification of the image display device inExample 1. FIG. 15 illustrates a schematic view of the display device ofExample 3 as viewed from the front, and FIG. 16 illustrates a schematicview thereof as viewed from above.

In Example 3, the light guide device 220 constituting the image displaydevice 200A includes a first deflecting unit (not illustrated) includinga reflecting mirror, a transparent member 221 such as a glass plate or aplastic plate, and a second deflecting unit 223 including asemi-transmissive mirror. The casing 115 housing the image formingdevice 111 and the lens system 114 is attached to the front portion 11.In addition, the second deflecting unit 223 is attached to thetransparent member 221, and the transparent member 221 is attached tothe image forming device 111.

In Example 3, light which has been emitted from the image forming device111 (not specifically illustrated) in FIGS. 15 and 16) housed in thecasing 115 and has passed through the lens system 114 (not specificallyillustrated in FIGS. 15 and 16) is deflected by the first deflectingunit. The light deflected by the first deflecting unit is propagated inthe transparent member 221, is deflected by the second deflecting unit223, and is emitted toward the pupil 21 of the observer 20. Note thatlight deflected by the first deflecting unit without being propagated inthe transparent member 221 may be propagated in air, may be deflected bythe second deflecting unit 223, and may be emitted toward the pupil 21of the observer 20.

The display device of Example 3 has substantially the same configurationand structure as those of the display device of Example 1 except for theabove difference, and therefore detailed description thereof will beomitted.

EXAMPLE 4

Example 4 is also a modification of the image display device inExample 1. FIG. 17 illustrates a schematic view of the display device ofExample 4 as viewed from above. Note that the imaging device 17 is notillustrated in FIG. 17.

In Example 4, the light guide device 230 constituting the image displaydevice 200B includes a semi-transmissive mirror 233 on which lightemitted from the image forming device 111 is incident and from which thelight is emitted toward the pupil 21 of the observer 20. That is, thelight guide device 230 includes a glass plate 231, and thesemi-transmissive mirror 233 is formed on the glass plate 231. The imageforming device 111 can have similar configuration and structure to theimage forming device 111 described in Example 1. However, in Example 4,unlike Example 1, light emitted from the image forming device 111disposed in the casing 115 is propagated inside an optical fiber (notillustrated), and is, for example, incident on the lens system 114attached to the portion 11′ of the frame 10 near a nose pad. The lightfrom the lens system 114 is incident on the semi-transmissive mirror233. Alternatively, the light emitted from the image forming device 111disposed in the casing 115 is propagated in an optical fiber (notillustrated), and is, for example, incident on the lens system 114disposed above portions of the frame 10 corresponding to both eyes. Thelight from the lens system 114 is incident on the semi-transmissivemirror 233. Alternatively, the light emitted from the image formingdevice 111 disposed in the casing 115 passes through the lens system 114disposed in the casing 115, and is directly incident on thesemi-transmissive mirror 233. Then, light reflected by thesemi-transmissive mirror 233 is incident on the pupil 21 of the observer20. The display device of Example 4 has substantially the sameconfiguration and structure as those of the display device of Example 1except for the above difference, and therefore detailed descriptionthereof will be omitted.

EXAMPLE 5

Example 5 is a modification of Examples 1 to 3. As illustrated in theconceptual diagram of an image display device in FIG. 18, the schematicview of the display device as viewed from above in FIG. 19, and theschematic view thereof viewed from a side in FIG. 20, in the displaydevice of Example 5, a light shielding member 401 is disposed orprovided outside the second surface 121B or 131B of the light guideplate 121 or 131 so as to cover the first deflecting unit 122 or 132.Here, orthogonally projected images of the first deflecting unit 122 or132 to the light guide plate 121 or 131 are included in an orthogonallyprojected image of the light shielding member 401 to the light guideplate 121 or 131.

Specifically, for example, in a region of the light guide device 120 or130 on which light emitted from the image forming device 111 isincident, specifically, in a region where the first deflecting unit 122or 132 is provided, the light shielding member 401 for shieldingincidence of external light on the light guide device 120 or 130 isdisposed. Here, the region of the light guide device 120 or 130 on whichlight emitted from the image forming device 111 is incident is includedin a projected image of the light shielding member 401 on the lightguide device 120 or 130. The light shielding member 401 is disposed awayfrom the light guide device 120 or 130 on the opposite side to a sidewhere the image forming device 111 is disposed in the light guide device120 or 130. The light shielding member 401 is manufactured, for example,from an opaque plastic material. The light shielding member 401integrally extends from the casing 115 of the image forming device 111,is attached to the casing 115 of the image forming device 111, extendsintegrally from the frame 10, is attached to the frame 10, or isattached to the light guide device 120 or 130. Incidentally, in theillustrated example, the light shielding member 401 integrally extendsfrom the casing 115 of the image forming device 111. In this way, thelight shielding member 401 for shielding incidence of external light onthe light guide device 120 or 130 is disposed in a region on which lightemitted from the image forming device is incident in the light guidedevice 120 or 130. Therefore, external light is not incident on theregion on which light emitted from the image forming device 111 isincident in the light guide device 120 or 130, specifically on the firstdeflecting unit 122 or 132. Therefore, image display quality in adisplay device is not deteriorated by generation of undesirable straylight or the like.

Alternatively, as illustrated in FIG. 21, a light shielding member 402is disposed in a portion of the light guide device 120 or 130 on theopposite side to a side where the image forming device 111 is disposed.Specifically, by printing an opaque ink on the light guide device 120 or130 (specifically, a transparent protective member 124 covering thesecond surface 121 B or 131 B of the light guide plate 121 or 131), thelight shielding member 402 can be formed. Outer edge portions of thelight guide plate 121 or 131 and an outer edge portion of thetransparent protective member 124 are sealed with a sealing member 125,or are bonded to each other. Note that the light shielding member 401can be combined with the light shielding member 402. The light shieldingmembers 401 and 402 can also be applied to the light guide device 220described in Example 3.

EXAMPLE 6

Example 6 is a modification of Examples 1 to 5. FIG. 22 illustrates aconceptual diagram of an image display device of Example 6. FIG. 23illustrates a schematic view of the display device of Example 6 asviewed from above. FIG. 24A illustrates a schematic view thereof asviewed from a side. In addition, FIG. 24B illustrates a schematic frontview of a light guide device and a light control device. FIG. 25A aillustrates a schematic cross-sectional view of the light controldevice. FIG. 25B illustrates a schematic plan view of the light controldevice.

In Example 6, a light control device 500 is disposed on a second surfaceside of the light guide plate 121 or 131. The light control device 500adjusts the amount of external light incident from an outside. Inaddition, a virtual image forming region of the light guide device 120or 130 overlaps with the light control device 500. If a virtual image isformed in a part of the virtual image forming region on the basis oflight emitted from the image forming device 111, the light controldevice 500 is controlled such that a light shielding ratio of a virtualimage projection region 511 of the light control device 500 including aprojected image of a virtual image on the light control device 500 ishigher than a light shielding ratio of another region 512 of the lightcontrol device 500. Incidentally, the position of the virtual imageprojection region 511 is not fixed in the light control device 500, butvaries depending on the formation position of a virtual image. Inaddition, the number of the virtual image projection regions 511 alsovaries depending on the number of virtual images (the number of a seriesof virtual image groups, the number of blocked virtual image groups, andthe like).

During operation of the light control device 500, if the light shieldingratio of a virtual image projection region of the light control device500 including a projected image of a virtual image on the light controldevice 500 is assumed to be “1”, the light shielding ratio of the otherregion 512 of the light control device 500 is, for example, 0.95 orless. Alternatively, the light shielding ratio of the other region ofthe light control device 500 is, for example, 30% or less. Meanwhile,during operation of the light control device 500, the light shieldingratio of the virtual image projection region 511 of the light controldevice 500 is 35% to 99%, for example, 80%. As described above, thelight shielding ratio of the virtual image projection region 511 may beconstant, or may vary depending on illuminance of an environment inwhich the display device is placed, as described later.

In Example 6 or either one of Examples 7 and 8 described later, thelight control device 500 which is a kind of optical shutter foradjusting the amount of external light incident from an outside isdisposed on the opposite side to a side where the image forming device111 is disposed in the light guide device 120 or 130. That is, the lightcontrol device 500 is disposed in a region of the light guide device 120or 130 on the opposite side to the observer 20. In this way, the lightguide device 120 or 130 and the light control device 500 are disposed inthis order from an observer side, but the light control device 500 andthe light guide device 120 or 130 may be disposed in this order. Inaddition, the transparent protective member 124 also serves as a firstsubstrate 501 of the light control device 500. This makes it possible toreduce the weight of the entire display device, and there is no fear tocause a user of the display device to feel uncomfortable. In addition, asecond substrate 503 can be thinner than the transparent protectivemember 124. A similar configuration can be used also in Examples 7 and8. However, the present disclosure is not limited thereto, and thetransparent protective member 124 and the first substrate 501 of thelight control device 500 may be constituted by different members. Thesize of the light control device 500 may be the same as, larger than, orsmaller than that of the light guide plate 121 or 131. In short, thevirtual image formation region (second deflecting unit 123 or 133) onlyneeds to be located within a projected image of the light control device500. A connector (not illustrated) is attached to the light controldevice 500, and the light control device 500 is electrically connectedto a control circuit (specifically, control device 18) for controlling alight shielding ratio of the light control device 500 via the connectorand wiring.

In Example 6 or either one of Examples 7 and 8 described later, asillustrated in the schematic cross-sectional view in FIG. 25A and theschematic plan view in FIG. 25B, the light control device 500 includesthe first substrate 501, the second substrate 503 facing the firstsubstrate 501, a first transparent electrode 502 provided on a surfacefacing the first substrate 501 facing the second substrate 503, a secondtransparent electrode 504 provided on a surface facing the secondsubstrate 503 facing the first substrate 501, and a light control layer505 sandwiched between the first transparent electrode 502 and thesecond transparent electrode 504. In addition, the first transparentelectrode 502 includes a plurality of band-shaped first transparentelectrode segments 502A extending in a first direction. The secondtransparent electrode 504 includes a plurality of band-shaped secondtransparent electrode segments 504A extending in a second directiondifferent from the first direction. A light shielding ratio of a portionof the light control device corresponding to an overlap region betweenthe first transparent electrode segments 502A and the second transparentelectrode segments 504A (minimum unit region 508 in which the lightshielding ratio of the light control device changes) is controlled onthe basis of control of voltages applied to the first transparentelectrode segments 502A and the second transparent electrode segments504A. That is, the light shielding ratio is controlled on the basis of asimple matrix method. The first direction is perpendicular to the seconddirection. Specifically, the first direction extends in a transversedirection (X-axis direction), and the second direction extends in alongitudinal direction (Z-axis direction).

The second substrate 503 includes a plastic material. In addition, eachof the first transparent electrode 502 and the second transparentelectrode 504 includes a transparent electrode including indium-tincomposite oxide (ITO), and is formed on the basis of a combination of aPVD method such as a sputtering method and a lift-off method. Aprotective layer 506 including an SiN layer, an SiO₂ layer, an Al₂O₃layer, a TiO₂ layer, or a laminated film thereof is formed between thesecond transparent electrode 504 and the second substrate 503. Byforming the protective layer 506, an ion blocking property preventingtransfer of ions, water-proofness, moisture-proofness, and scratchresistance can be imparted to the light control device 500. In addition,the transparent protective member 124 (first substrate 501) and thesecond substrate 503 are sealed with a sealing material 507 including anultraviolet curable resin or a thermosetting resin, such as anultraviolet curable epoxy resin or an epoxy resin cured by anultraviolet ray and heat. The first transparent electrode 502 and thesecond transparent electrode 504 are connected to the control device 18via a connector and wiring (not illustrated).

A light shielding ratio (light transmittance) of the light controldevice 500 can be controlled by a voltage applied to the firsttransparent electrode 502 and the second transparent electrode 504.Specifically, for example, if a voltage is applied to the secondtransparent electrode 504 while the first transparent electrode 502 isgrounded, a light shielding ratio of the light control layer 505changes. A potential difference between the first transparent electrode502 and the second transparent electrode 504 may be controlled, or avoltage applied to the first transparent electrode 502 and a voltageapplied to the second transparent electrode 504 may be independentlycontrolled.

Incidentally, if the number of pixels of the virtual image formingregion (second deflecting unit 123 or 133) in a transverse direction inthe light control device 500 is represented by M₀ and the number ofpixels thereof in a longitudinal direction is represented by N₀, thenumber M₁×N₁ of a minimum unit region 508 in which a light shieldingratio of the light control device 500 changes satisfies, for example,M₀=M₁ (that is, k=1) and N₀=N₁ (that is, k′=1) provided that M₁/M₀=k andN₁/N₀=k′. However, the present disclosure is not limited thereto, butmay satisfy 1.1≤k, preferably 1.1≤k≤1.5, and more preferably 1.15≤k≤1.3and 1.1≤k′, and preferably 1.1≤k′≤1.5 and more preferably 1.15≤k′≤1.3.Values of k and k′ may be the same as or different from each other. InExamples, k=k′=1 is satisfied.

In Example 6 or either one of Examples 7 and 8 described later, thelight control device 500 includes an optical shutter applying a colorchange of a substance generated by an oxidation-reduction reaction of anelectrochromic material. Specifically, the light control layer includesan electrochromic material. More specifically, the light control layerhas a laminated structure of a WO₃ layer 505A/Ta₂O₅ layer505B/Ir_(X)Sn_(1-X)O layer 505C from the second transparent electrodeside. The WO₃ layer 505A develops color reductively. In addition, theTa₂O₅ layer 505B constitutes a solid electrolyte, and theIr_(X)Sn_(1-X)O layer 505C develops color oxidatively.

In the Ir_(X)Sn_(1-X)O layer, Ir and H₂O react with each other, andexist as iridium hydroxide Ir(OH)_(n). If a negative potential isapplied to the second transparent electrode 504 and a positive potentialis applied to the first transparent electrode 502, a proton H⁺ movesfrom the Ir_(X)Sn_(1-X)O layer to the Ta₂O₅ layer, an electron isreleased to the first transparent electrode 502, the following oxidationreaction proceeds, and the Ir_(X)Sn_(1-X)O layer is colored.

Ir(OH)_(n)→IrO_(X)(OH)_(n-X) (colored)+X.H⁺+X·e⁻

Meanwhile, a proton H⁺ in the Ta₂O₅ layer moves into the WO₃ layer, andan electron is injected from the second transparent electrode 504 intothe WO₃ layer. In the WO₃ layer, the following reduction reactionproceeds, and the WO₃ layer is colored.

WO₃+X.H⁺+X·e⁺→H_(X)WO₃ (colored)

Conversely, if a positive potential is applied to the second transparentelectrode 504 and a negative potential is applied to the firsttransparent electrode 502, in the Ir_(X)Sn_(1-X)O layer, a reductionreaction proceeds in the opposite direction to the above, anddecolorization occurs. In the WO₃ layer, an oxidation reaction proceedsin the opposite direction to the above, and decolorization occurs. Notethat the Ta₂O₅ layer contains H₂O. H₂O is ionized by applying a voltageto the first transparent electrode and the second transparent electrode.The Ta₂O₅ includes a proton H⁺ and an OH⁻ ion, contributing to acoloring reaction and a decoloring reaction.

Information and data regarding an image displayed on the image displaydevice 100A or 100B or a signal to be received by a receiving device isrecorded, kept, and stored, for example, in a so-called cloud computeror a server. By inclusion of a communication unit (sending/receivingdevice) such as a mobile phone or a smartphone in the display device orby incorporation of a communication unit (receiving device) into thecontrol device (control circuit or control unit) 18, various kinds ofinformation, data, and signals can be transmitted and exchanged betweenthe cloud computer or the server and the display device via thecommunication unit, a signal based on various kinds of information anddata, that is, a signal for displaying an image in the image displaydevice 100A or 100B can be received, and the receiving device canreceive the signal.

Specifically, if an observer inputs a request for “information” to beobtained to a mobile phone or a smartphone, the mobile phone or thesmartphone accesses a cloud computer or a server to obtain “information”from the cloud computer or the server. In this way, the control device18 receives a signal for displaying an image in the image display device100A or 100B. The control device 18 performs well-known image processingon the basis of this signal, and displays “information” in the imageforming device 111 as an image. The “information” is displayed as avirtual image at a predetermined position controlled by the controldevice 18 on the basis of light emitted from the image forming device111 in the light guide device 120 or 130. That is, a virtual image isformed in a part of the virtual image forming region (second deflectingunit 123 or 133).

In addition, in a case where the light control device 500 is provided,the light control device 500 is controlled such that a light shieldingratio of the virtual image projection region 511 of the light controldevice 500 including a projected image of a virtual image on the lightcontrol device 500 is higher than a light shielding ratio of the otherregion 512 of the light control device 500. Specifically, the controldevice 18 controls voltages applied to the first transparent electrode502 and the second transparent electrode 504. Here, the size andposition of the virtual image projection region 511 of the light controldevice 500 are determined on the basis of a signal for displaying animage in the image forming device 111.

In some cases, a signal for displaying an image in the image displaydevice 100A or 100B may be stored in the display device (specifically,the control device 18 or the image information storage device 18A).

Alternatively, an image imaged by the imaging device 17 included in thedisplay device may be sent to a cloud computer or a server via acommunication unit. The cloud computer or the server may retrievevarious kinds of information and data corresponding to the image imagedby the imaging device 17. The various kinds of information and dataretrieved may be sent to the display device via the communication unit.An image of the various kinds of information and data retrieved may bedisplayed on the image display device 100A or 100B. In addition, ifinput of “information” is performed together with such a form, forexample, information such as a place where an observer is located or adirection in which the observer is facing can be weighted. Therefore,“Information” can be displayed on the image forming device 111 withhigher accuracy.

A light shielding ratio of the virtual image projection region 511 ofthe light control device 500 may be increased before a virtual image isformed on the light guide device 120 or 130 on the basis of lightemitted from the image forming device 111. Time from an increase in thelight shielding ratio of the virtual image projection region 511 of thelight control device 500 to formation of a virtual image may be 0.5 to30 seconds, for example, but is not limited thereto. In this way, anobserver can know in advance where and when a virtual image is formed inthe light guide device, and therefore virtual image visibility of theobserver can be improved. The light shielding ratio of the virtual imageprojection region 511 of the light control device 500 may increasesequentially as time elapses. That is, a so-called fade-in state can beformed.

In a case where no virtual image is formed, a light shielding ratio ofthe entire light control device 500 only needs to be set to the samevalue as a light shielding ratio of another region of the light controldevice 500. When formation of a virtual image is completed and thevirtual image disappears, the light shielding ratio of the virtual imageprojection region 511 of the light control device 500 including aprojected image of the virtual image on the light control device 500 maybe immediately set to the same value as the light shielding ratio ofanother region of the light control device 500, or may be controlled soas to be the same value as the light shielding ratio of another regionof the light control device 500 over time (for example, in threeseconds). That is, a so-called fade-out state can be formed.

It is assumed that one virtual image is formed on the light guide device120 or 130 on the basis of light emitted from the image forming device111 and then a subsequent virtual image different from the one virtualimage is formed. In this case, if the area of the virtual imageprojection region 511 of the light control device 500 corresponding toone virtual image is represented by S₁ and the area of the virtual imageprojection region 511 of the light control device 500 corresponding to asubsequent virtual image is represented by S₂, in a case of S₂/S₁<0.8 or1<S₂/S₁, the virtual image projection region 511 of the light controldevice 500 on which a subsequent virtual image is formed may be a regionof the light control device 500 including a projected image of asubsequent virtual image on the light control device 500 (refer to FIGS.26A, 26B, and 26C), and in a case of 0.8≤S₂/S₁≤1, the virtual imageprojection region 511 of the light control device 500 on which asubsequent virtual image is formed may be a region of the light controldevice 500 including a projected image of one virtual image on the lightcontrol device 500 That is, from formation of one virtual image toformation of a subsequent virtual image, in a case where the area of avirtual image projection region is reduced by 0% to 20%, a virtual imageprojection region corresponding to one virtual image can be held (thatis, the state illustrated in FIG. 26A is held).

In addition, as illustrated in FIG. 27, assuming a virtual rectangle 513circumscribed with a virtual image formed in the light guide device 120or 130, the virtual image projection region 511 of the light controldevice 500 may be larger than the virtual rectangle 513. In addition, inthis case, if the lengths of the virtual rectangle 513 circumscribedwith a virtual image formed in the light guide device 120 or 130 in atransverse direction and a longitudinal direction are represented byL_(1-T) and L_(1-L), respectively, and the shape of the virtual imageprojection region 511 of the light control device 500 is a rectangularshape having lengths of L_(2-T) and L_(2-L) in the transverse directionand the longitudinal direction, respectively,

1.0≤L_(2-T)/L_(1-T)≤1.5 and

1.0≤L_(2-L)/L_(1-L)≤1.5

are preferably satisfied. Note that “ABCD” is formed as a virtual imagein FIG. 27.

The light control device 500 may be in an operation state all the time,may be determined to be in an operation/non-operation (ON/OFF) state byinstruction (operation) of an observer, or may be normally in anon-operation state while starting operation on the basis of a signalfor displaying an image in the image display device 100A or 100B. Inorder to determine an operation/non-operation state by instruction(operation) of an observer, for example, the display device only needsto further include a microphone via which a voice is input and the lightcontrol device 500 is thereby controlled. Specifically, switching ofoperation/non-operation of the light control device 500 only needs to becontrolled according to an instruction based on a real voice of anobserver. Alternatively, information to be obtained may be input byvoice input. Alternatively, the display device only needs to furtherinclude an infrared input/output device to control operation of thelight control device 500. Specifically, switching ofoperation/non-operation of the light control device 500 only needs to becontrolled by detection of the blink of an observer by the infraredinput/output device.

As described above, in the display device of Example 6, when a virtualimage is formed in a part of a virtual image forming region on the basisof light emitted from an image forming device, a light control device iscontrolled such that a light shielding ratio of a virtual imageprojection region of the light control device including a projectedimage of a virtual image on the light control device is higher than alight shielding ratio of another region of the light control device.Therefore, high contrast can be imparted to a virtual image observed byan observer. In addition, the entire light control device is not aregion having a high light shielding ratio, but only a narrow regionsuch as a virtual image projection region of the light control deviceincluding a projected image of a virtual image on the light controldevice is a region having a high light shielding ratio. Therefore, anobserver using the display device can reliably and safely recognize anexternal environment.

A frame includes a front portion disposed in front of an observer, twotemple portions rotatably attached to both ends of the front portion viahinges, and a nose pad. The light control device 500 may be disposed inthe front portion. In addition, the light guide device may be attachedto the light control device 500. Incidentally, the light guide devicemay be attached to the light control device 500 while being in a closecontact thereto, or may be attached to the light control device 500 witha gap therebetween. Furthermore, in these cases, as described above, thefront portion may have a rim, and the light control device 500 may befitted in the rim. Alternatively, the light guide plate 121 or 131(first substrate 501) and/or the second substrate 503 may be fitted inthe rim, the light control device 500 and the light guide plate 121 or131 may be fitted in the rim, or the light guide plate 121 or 131 may befitted in the rim.

The light control layer 505 may be constituted by an optical shutterincluding a liquid crystal display device. In this case, specifically,the light control layer 505 may include a liquid crystal material layercontaining, for example, a twisted nematic (TN) type liquid crystalmaterial or a super twisted nematic (STN) type liquid crystal material.The first transparent electrode 502 and the second transparent electrode504 are patterned. A light shielding ratio (light transmittance) of theregion 512 as a part of the light control device 500 can be changed to alight shielding ratio different from a light shielding ratio of anotherregion. Alternatively, one of the first transparent electrode 502 andthe second transparent electrode 504 is a so-called solid electrode notpatterned, the other is patterned and connected to a TFT. Then, a lightshielding ratio of the minimum unit region 508 in which a lightshielding ratio of the light control device 500 changes is controlled bythe TFT. That is, the light shielding ratio may be controlled on thebasis of an active matrix method. It goes without saying that thecontrol of the light shielding ratio based on the active matrix methodcan be applied to the light control device 500 described in Example 6 oreither one of Examples 7 and 8 described later.

In addition, it is also possible to use an optical shutter forcontrolling the light shielding ratio (light transmittance) by anelectrowetting phenomenon. Specifically, a first transparent electrodeand a second transparent electrode are provided, and a space between thefirst transparent electrode and the second transparent electrode isfilled with an insulating first liquid and a conductive second liquid.Then, by applying a voltage between the first transparent electrode andthe second transparent electrode, the shape of an interface formed bythe first liquid and the second liquid changes, for example, from a flatshape to a curved shape, and the light shielding ratio (lighttransmittance) can be thereby controlled. Alternatively, an opticalshutter applying an electrodeposition method (electrodeposition/electricfield deposition) based on an electrodeposition/dissociation phenomenongenerated by a reversible oxidation-reduction reaction of metal (forexample, silver particles) can be used. Specifically, by dissolving Ag₊and I⁻ in an organic solvent and applying an appropriate voltage to anelectrode, Ag⁺ is reduced to precipitate Ag, and a light shielding ratio(light transmittance) of the light control device is thereby decreased.Meanwhile, Ag is oxidized to be dissolved as Ag⁺, and the lightshielding ratio (light transmittance) of the light control device isthereby increased.

In some cases, light passing through the light control device can becolored to a desired color by the light control device. In this case, acolor to which light is colored by the light control device can bevariable. Specifically, for example, it is only required to laminate alight control device colored in red, a light control device colored ingreen, and a light control device colored in blue.

The light control device may be detachably disposed in a region fromwhich light of the light guide device is emitted. In this way, in orderto detachably dispose the light control device, for example, it is onlyrequired to attach the light control device to the light guide deviceusing a screw manufactured from transparent plastic, and to connect thelight control device to a control circuit (for example, included in thecontrol device 18 for controlling an image forming device) forcontrolling a light shielding ratio (light transmittance) of the lightcontrol device via a connector and wiring.

It goes without saying that the light control device of Example 7described above can be applied to the display device described in anyone of Examples 3 to 5.

EXAMPLE 7

Example 7 is a modification of Example 6. FIG. 28A illustrates aschematic view of the display device of Example 7 as viewed from above.In addition, FIG. 28B illustrates a schematic diagram of a circuit forcontrolling an environmental illuminance measuring sensor.

The display device of Example 7 further includes an environmentalilluminance measuring sensor 521 for measuring illuminance of anenvironment where the display device is placed, and controls a lightshielding ratio of the light control device 500 on the basis of ameasurement result of the environmental illuminance measuring sensor521. At the same time, or independently, the display device of Example 7controls brightness of an image formed by the image forming device 111on the basis of the measurement result of the environmental illuminancemeasuring sensor 521. The environmental illuminance measuring sensor 521having a well-known configuration and structure only needs to bedisposed, for example, at an outer end portion of the light guide device120 or 130 and an outer end portion of the light control device 500. Theenvironmental illuminance measuring sensor 521 is connected to thecontrol device 18 via a connector and wiring (not illustrated). Thecontrol device 18 includes a circuit for controlling the environmentalilluminance measuring sensor 521. The circuit for controlling theenvironmental illuminance measuring sensor 521 includes an illuminancecalculating circuit for receiving a measurement value from theenvironmental illuminance measuring sensor 521 to determine illuminance,a comparison calculating circuit for comparing an illuminance valuedetermined by the illuminance calculating circuit with a standard value,and an environmental illuminance measuring sensor control circuit forcontrolling the light control device 500 and/or the image forming device111 on the basis of the value determined by the comparison calculatingcircuit. These circuits may be constituted by well-known circuits. Incontrol of the light control device 500, a light shielding ratio of thelight control device 500 is controlled. Meanwhile, in control of theimage forming device 111, brightness of an image formed by the imageforming device 111 is controlled. Incidentally, control of the lightshielding ratio in the light control device 500 and control of thebrightness of an image in the image forming device 111 may be performedindependently or with correlation.

For example, when a measurement result of the environmental illuminancemeasuring sensor 521 becomes a predetermined value (first illuminancemeasurement value) or more, the light shielding ratio of the lightcontrol device 500 is set to a predetermined value (first lightshielding ratio) or more. Meanwhile, when a measurement result of theenvironmental illuminance measuring sensor 521 becomes a predeterminedvalue (second illuminance measurement value) or less, the lightshielding ratio of the light control device 500 is set to apredetermined value (second light shielding ratio) or less. Here, thefirst illuminance measurement value may be 10 lux, and the first lightshielding ratio may be any value of 99% to 70%, the second illuminancemeasurement value may be 0.01 lux, and the second light shielding ratiomay be any value of 49% to 1%.

Note that the environmental illuminance measuring sensor 521 in Example7 can be applied to the display device described in any one of Examples1 to 5. In addition, in a case where the display device includes theimaging device 17, the environmental illuminance measuring sensor 521can be constituted by a light receiving element for exposure measurementincluded in the imaging device 17.

In the display device of Example 7 or Example 8 described below, a lightshielding ratio of the light control device is controlled on the basisof a measurement result of the environmental illuminance measuringsensor, brightness of an image formed by the image forming device iscontrolled on the basis of a measurement result of the environmentalilluminance measuring sensor, a light shielding ratio of the lightcontrol device is controlled on the basis of a measurement result of thetransmitted light illuminance measuring sensor, and brightness of animage formed by the image forming device is controlled on the basis of ameasurement result of the transmitted light illuminance measuringsensor. Therefore, it is possible not only to impart a high contrast toa virtual image observed by an observer but also to optimize anobservation state of a virtual image depending on illuminance of anenvironment around the display device.

EXAMPLE 8

Example 8 is a modification of Example 6. FIG. 29A illustrates aschematic view of the display device of Example 8 as viewed from above.In addition, FIG. 29B illustrates a schematic diagram of a circuit forcontrolling a transmitted light illuminance measuring sensor.

The display device of Example 8 further includes a transmitted lightilluminance measuring sensor 522 for measuring illuminance based onlight which has passed through the light control device from an externalenvironment, that is, for measuring whether environmental light passesthrough the light control device and is incident at desired illuminanceadjusted, and controls a light shielding ratio of the light controldevice 500 on the basis of a measurement result of the transmitted lightilluminance measuring sensor 522. At the same time, or independently,the display device of Example 8 controls brightness of an image formedby the image forming device 111 on the basis of the measurement resultof the transmitted light illuminance measuring sensor 522. Thetransmitted light illuminance measuring sensor 522 having a well-knownconfiguration and structure is disposed closer to an observer than thelight guide device 120 or 130. Specifically, it is only required todispose the transmitted light illuminance measuring sensor 522, forexample, on an inner surface of the casing 115 or on a surface of thelight guide plate 121 or 131 on an observer side. The transmitted lightilluminance measuring sensor 522 is connected to the control device 18via a connector and wiring (not illustrated). The control device 18includes a circuit for controlling the transmitted light illuminancemeasuring sensor 522. The circuit for controlling the transmitted lightilluminance measuring sensor 522 includes an illuminance calculatingcircuit for receiving a measurement value from the transmitted lightilluminance measuring sensor 522 to determine illuminance, a comparisoncalculating circuit for comparing an illuminance value determined by theilluminance calculating circuit with a standard value, and a transmittedlight illuminance measuring sensor control circuit for controlling thelight control device 500 and/or the image forming device 111 on thebasis of the value determined by the comparison calculating circuit.These circuits may be constituted by well-known circuits. In control ofthe light control device 500, a light shielding ratio of the lightcontrol device 500 is controlled. Meanwhile, in control of the imageforming device 111, brightness of an image formed by the image formingdevice 111 is controlled. Incidentally, control of the light shieldingratio in the light control device 500 and control of the brightness ofan image in the image forming device 111 may be performed independentlyor with correlation. Furthermore, in a case where a measurement resultof the transmitted light illuminance measuring sensor 522 cannot becontrolled to desired illuminance in view of illuminance of theenvironmental illuminance measuring sensor 521, that is, in a case wherea measurement result of the transmitted light illuminance measuringsensor 522 is not desired illuminance, or in a case where even moredelicate illumination adjustment is desired, it is only required toadjust a light transmittance of the light control device while a valueof the transmitted light illuminance measuring sensor 522 is monitored.At least two transmitted light illuminance measuring sensors may bedisposed, and illuminance based on light which has passed through aportion with a high light shielding ratio and illuminance based on lightwhich has passed through a portion with a low light shielding ratio maybe measured.

Note that the transmitted light illuminance measuring sensor 522 inExample 8 can be applied to the display device described in any one ofExamples 1 to 5. Alternatively, the transmitted light illuminancemeasuring sensor 522 in Example 8 and the environmental illuminancemeasuring sensor 521 in Example 7 may be combined with each other. Inthis case, various tests may be performed, and control of a lightshielding ratio in the light control device 500 and control ofbrightness of an image in the image forming device 111 may be performedindependently or with correlation. By adjusting voltages applied to thefirst transparent electrode and the second transparent electrode in eachof the right eye light control device and the left eye light controldevice, light shielding ratios in the right eye light control device andthe left eye light control device can be equalized. A potentialdifference between the first transparent electrode and the secondtransparent electrode may be controlled, or a voltage applied to thefirst transparent electrode and a voltage applied to the secondtransparent electrode may be independently controlled. The lightshielding ratios in the right eye light control device and the left eyelight control device can be controlled, for example, on the basis of ameasurement result of the transmitted light illuminance measuring sensor522, or can be controlled and adjusted manually by observation ofbrightness of light which has passed through the right eye light controldevice and light guide device and brightness of light which has passedthrough the left eye light control device and light guide device by anobserver and operation of a switch, a button, a dial, a slider, a knob,or the like by the observer.

EXAMPLE 9

Example 9 relates to an optical device of the present disclosure,specifically, to a projector. As illustrated in the conceptual diagramof the optical device (projector) of Example 9 in FIG. 30, the opticaldevice (projector) of Example 9 includes an image forming device 111′and a lens system 114′ for projecting an image from the image formingdevice 111′ on an outside (for example, a screen). The image formingdevice 111′ has substantially a similar configuration and structure tothe image forming device 111 described in Example 1. Specifically, theimage forming device 111′ includes a plurality of (for example,1920×1080) pixels arranged in a two-dimensional matrix. Each pixelincludes the light emitting element 300 described in Example 1. Theimage forming device 111′ and the lens system 114′ are housed in acasing (not illustrated). Light emitted from the light emitting element300 constituting the image forming device 111′ is incident on the lenssystem 114′, and light emitted from the lens system 114′ is projected ona screen. By connecting the optical device of Example 9 to a DVD playeror a personal computer, an image can be projected on a screen on thebasis of an image signal output from the DVD player or the personalcomputer. Alternatively, the optical device of Example 9 can be used asa displaying device in which an observer directly observes an imageemitted from the optical device of Example 9. In this case, the lenssystem 114′ can be omitted in some cases.

Hitherto, the present disclosure has been described on the basis of thepreferable Examples. However, the present disclosure is not limited tothese Examples. The configurations and structures of the optical device,the display device (head mounted display), the image display device, theimage forming device, the light guide device, and the laminatedstructure described in Examples are illustrative and can beappropriately changed. For example, a surface relief type hologram(refer to U.S. Pat. No. 20040062505 A1) may be disposed on the lightguide plate. In the light guide device, a diffraction grating member maybe constituted by a transmission type diffraction grating member.Alternatively, one deflecting unit of the first deflecting unit and thesecond deflecting unit may be constituted by a reflection typediffraction grating member, and the other may be constituted by atransmission type diffraction grating member. Alternatively, thediffraction grating member may be a reflection type blazed diffractiongrating member. The display device of the present disclosure can also beused as a stereoscopic displaying device. In this case, if necessary, itis only required to detachably attach a polarizing plate or a polarizingfilm to the light guide device, or to bond a polarizing plate or apolarizing film to the light guide device.

In the optical device or the display device of the present disclosure,as illustrated in the schematic partial cross-sectional view of a lightemitting element cut along a virtual vertical plane in FIG. 31, thelight emitting element may further include a condenser lens 363 forcondensing light emitted from the through hole 360. In addition, asillustrated in the schematic partial cross-sectional view of a lightemitting element cut along a virtual vertical plane in FIG. 32, aprotective film 371 including, for example, SiO₂ may be formed on topsurfaces of the antireflection layer (light absorbing layer) 370, thecore portion 361, and the clad layer 362. An AR coating layer may beformed on the protective film 371, or a moth-eye structure or a fineuneven structure may be formed on a top surface of the protective film371.

In manufacturing a deflecting unit, by superimposing two photopolymerlayers and making ultraviolet irradiation amounts of a photopolymer filmconstituting a lower layer and a photopolymer film constituting an upperlayer different from each other, two diffraction grating layers havingdifferent slant angles of diffraction grating members which have beensubjected to a heat treatment and the same surface pitch ∧ of aninterference fringe on a surface can be formed. In addition this makesit possible to adjust a width and efficiency of a diffractionwavelength. By matching the diffraction wavelength with a wavelength ofa light source, it is possible to manufacture a high brightness lightguide device. Specifically, by making a difference of about 5 J inultraviolet irradiation amount at a wavelength of 365 nm, a wavelengthdifference of about 30 nm can be obtained. A heat treatment is performedat a temperature of 100° C. to 120° C. in a conventional oven.

FIG. 33A illustrates a schematic view of a modified example of the lightguide device constituting the light guide device described in Example 4as viewed from above. Note that a light control device is notillustrated in FIGS. 33A and 33B.

In the example illustrated in FIG. 33A, light which has passed throughthe image forming device 111 and the lens system 114 travels through alight guide member 612 and collides with a semi-transmissive mirror 613.A part of the light passes through the semi-transmissive mirror 613,collides with a reflecting plate 614, is reflected, and collides withthe semi-transmissive mirror 613 again. A part of the light is reflectedby the semi-transmissive mirror 613 and travels toward the pupil 21 ofthe observer 20. As described above, the light guide device includes thelight guide member 612, the semi-transmissive mirror 613, and thereflecting plate 614. The semi-transmissive mirror 613 corresponds to avirtual image forming region of the light guide device.

Alternatively, FIGS. 33B and 33C illustrate a schematic view of a lightguide device in another modified example of the display device ofExample 4 as viewed from above and a schematic view thereof as viewedfrom the front, respectively. This light guide device includes ahexahedron prism 622 and a convex lens 625. Light which has passedthrough the image forming device 111 and the lens system 114 is incidenton a prism 622, collides with a prism surface 623, is reflected, travelsthrough the prism 622, collides with a prism surface 624, is reflected,and reaches the pupil 21 of the observer 20 via the convex lens 625. Theprism surface 623 and the prism surface 624 are inclined in a facingdirection, and a planar shape of the prism 622 is a trapezoid,specifically, an isosceles trapezoid. Mirror coating has been applied tothe prism surfaces 623 and 624. If a thickness (height) of a portion ofthe prism 622 facing the pupil 21 is thinner than 4 mm which is anaverage pupil diameter of a human, the observer 20 can view a virtualimage from the prism 622 superimposed on an image of an outside world.

Note that the present disclosure may have the following configurations.

[A01] An optical device including:

-   -   an image forming device; and    -   a lens system for projecting an image from the image forming        device on an outside, in which    -   the image forming device includes light emitting elements        arranged in a two- dimensional matrix,    -   each of the light emitting elements has a laminated structure        including at least one layer of a light emitting laminate        including a first electrode, a second electrode, and a light        emitting layer provided between the first electrode and the        second electrode,    -   the laminated structure has a through hole which is formed in a        lamination direction of the laminated structure and through        which light from the light emitting layer is emitted toward the        lens system, and    -   an antireflection layer is formed in a portion of the laminated        structure facing the lens system.

[A02] The optical device according to [A01], in which the antireflectionlayer is formed up to an edge portion of the through hole in thelaminated structure.

[A03] The optical device according to [A01] or [A02], in which each ofthe light emitting elements has a laminated structure including threelayers of a light emitting laminate that emits red light, a lightemitting laminate that emits green light, and a light emitting laminatethat emits blue light.

[A04] The optical device according to any one of [A01] to [A03], inwhich each of the light emitting elements further includes a condenserlens for condensing light emitted from the through hole.

[A05] The optical device according to any one of [A01] to [A04], inwhich

-   -   the image forming device further includes a circuit board on        which a light emitting element driving circuit is provided, and    -   each of the light emitting elements is connected to the light        emitting element driving circuit provided on the circuit board.

[A06] The optical device according to any one of [A01] to [A05], inwhich the image forming device further includes a support substrateconstituting the laminated structure on a light emitting side.

[B01] <<Display device>>

-   -   A display device including:    -   (a) a frame mounted on the head of an observer; and    -   (b) an image display device attached to the frame, in which    -   the image display device includes:    -   (A) an image forming device;    -   (B) a light guide device for guiding an image from the image        forming device to the pupil of an observer; and    -   (C) a lens system for making an image from the image forming        device incident on the light guide device,    -   the image forming device includes light emitting elements        arranged in a two-dimensional matrix,    -   each of the light emitting elements has a laminated structure        including at least one layer of a light emitting laminate        including a first electrode, a second electrode, and a light        emitting layer provided between the first electrode and the        second electrode,    -   the laminated structure has a through hole which is formed in a        lamination direction of the laminated structure and through        which light from the light emitting layer is emitted toward the        lens system, and    -   an antireflection layer is formed in a portion of the laminated        structure facing the lens system.

[B02] The display device according to [B01], in which the antireflectionlayer is formed up to an edge portion of the through hole in thelaminated structure.

[B03] The display device according to [B01] or [B02], in which each ofthe light emitting elements has a laminated structure including threelayers of a light emitting laminate that emits red light, a lightemitting laminate that emits green light, and a light emitting laminatethat emits blue light.

[B04] The display device according to any one of [B01] to [B03], inwhich each of the light emitting elements further includes a condenserlens condensing light emitted from the through hole.

[B05] The display device according to any one of [B01] to [B04], inwhich the image forming device further includes a circuit board on whicha light emitting element driving circuit is provided, and each of thelight emitting elements is connected to the light emitting elementdriving circuit provided on the circuit board.

[B06] The display device according to any one of [B01] to [B05], inwhich the image forming device further includes a support substrateconstituting the laminated structure on a light emitting side.

[C01] The display device according to any one of [B01] to [B06], furtherincluding a light control device for adjusting the amount of externallight incident from an outside, in which

-   -   a virtual image forming region in which a virtual image is        formed on the basis of light emitted from the image forming        device in the light guide device overlaps with the light control        device, and    -   if a virtual image is formed in a part of the virtual image        forming region on the basis of light emitted from the image        forming device, the light control device is controlled such that        a light shielding ratio of a virtual image projection region of        the light control device including a projected image of a        virtual image on the light control device is higher than a light        shielding ratio of another region of the light control device.

[C02] The display device according to [C01], in which during operationof the light control device, if a light shielding ratio of a virtualimage projection region of the light control device including aprojected image of a virtual image on the light control device isassumed to be “1”, a light shielding ratio of another region of thelight control device is 0.95 or less.

[C03] The display device according to [C01] or [C02], in which duringoperation of the light control device, the light shielding ratio of thevirtual image projection region of the light control device is 35% to99%.

[C04] The display device according to any one of [C01] to [C03], inwhich the light shielding ratio of the virtual image projection regionof the light control device is increased before a virtual image isformed on the light guide device on the basis of light emitted from theimage forming device.

[C05] The display device according to any one of [C01] to [C04], inwhich

-   -   in a case where one virtual image is formed on the light guide        device on the basis of light emitted from the image forming        device and then a subsequent virtual image different from the        one virtual image is formed, if the area of the virtual image        projection region of the light control device corresponding to        the one virtual image is represented by S₁ and the area of the        virtual image projection region of the light control device        corresponding to the subsequent virtual image is represented by        S₂,    -   in a case of S₂/S₁<0.8 or 1<S₂/S₁, the virtual image projection        region of the light control device on which the subsequent        virtual image is formed is a region of the light control device        including a projected image of the subsequent virtual image on        the light control device, and    -   in a case of 0.8 5≤S₂/S₁≤1, the virtual image projection region        of the light control device on which the subsequent virtual        image is formed is a region of the light control device        including a projected image of the one virtual image on the        light control device.

[C06] The display device according to any one of [C01] to [C05], inwhich

-   -   assuming a virtual rectangle circumscribed with a virtual image        formed in the light guide device,    -   the virtual image projection region of the light control device        is larger than the virtual rectangle.

[C07] The display device according to [C06], in which

-   -   if the lengths of the virtual rectangle circumscribed with a        virtual image formed in the light guide device in a transverse        direction and a longitudinal direction are represented by        L_(1-T) and L_(1-L), respectively, and the shape of the virtual        image projection region of the light control device is a        rectangular shape having lengths of L_(2-T) and L_(2-L) in the        transverse direction and the longitudinal direction,        respectively,

1.0≤L_(2-T)/L_(1-T)≤1.5 and

1.0≤L_(2-L)/L_(1-L)≤1.5

-   -   are satisfied.

[C08] The display device according to any one of [C01] to [C07], inwhich

-   -   the light control device includes:    -   a first substrate;    -   a second substrate facing the first substrate;    -   a first transparent electrode provided on a surface facing the        first substrate facing the second substrate;    -   a second transparent electrode provided on a surface facing the        second substrate facing the first substrate; and    -   a light control layer sandwiched between the first transparent        electrode and the second transparent electrode.

[C09] The display device according to [C08], in which

-   -   the first transparent electrode includes a plurality of        band-shaped first transparent electrode segments extending in a        first direction,    -   the second transparent electrode includes a plurality of        band-shaped second transparent electrode segments extending in a        second direction different from the first direction, and    -   a light shielding ratio of a portion of the light control device        corresponding to an overlap region between the first transparent        electrode segments and the second transparent electrode segments        is controlled on the basis of control of voltages applied to the        first transparent electrode segments and the second transparent        electrode segments.

[C10] The display device according to any one of [C01] to [C09], furtherincluding an environmental illuminance measuring sensor for measuringilluminance of an environment where the display device is placed, inwhich

-   -   the display device controls a light shielding ratio of the light        control device on the basis of a measurement result of the        environmental illuminance measuring sensor.

[C11] The display device according to any one of [C01] to [C10], furtherincluding an environmental illuminance measuring sensor for measuringilluminance of an environment where the display device is placed, inwhich

-   -   the display device controls brightness of an image formed by the        image forming device on the basis of a measurement result of the        environmental illuminance measuring sensor.

[C12] The display device according to any one of [C01] to [C11], furtherincluding a transmitted light illuminance measuring sensor for measuringilluminance based on light which has passed through the light controldevice from an external environment, in which

-   -   the display device controls a light shielding ratio of the light        control device on the basis of a measurement result of the        transmitted light illuminance measuring sensor.

[C13] The display device according to any one of [C01] to [C12], furtherincluding a transmitted light illuminance measuring sensor for measuringilluminance based on light which has passed through the light controldevice from an external environment, in which

-   -   the display device controls brightness of an image formed by the        image forming device on the basis of a measurement result of the        transmitted light illuminance measuring sensor.

[C14] The display device according to [C12] or [C13], in which thetransmitted light illuminance measuring sensor is disposed closer to anobserver than the light guide device.

[C15] The display device according to any one of [C01] to [C14], inwhich light passing through the light control device is colored to adesired color by the light control device.

[C16] The display device according to [C15], in which a color to whichlight is colored by the light control device is variable.

[C17] The display device according to [C15], in which a color to whichlight is colored by the light control device is fixed.

[D01] The display device according to any one of [B01] to [B06], inwhich a light control device for adjusting the amount of external lightincident from an outside is disposed in a region of the light guidedevice facing at least the pupil of an observer.

[D02] The display device according to [D01], in which the light controldevice includes:

-   -   a first substrate facing the light guide device and a second        substrate facing the first substrate;    -   an electrode provided in each of the first substrate and the        second substrate; and    -   a light transmission control material layer sealed between the        first substrate and the second substrate.

[D03] The display device according to [D02], in which the firstsubstrate also serves as a member constituting the light guide device.

[D04] The display device according to [D02] or [D03], in which thesecond substrate is thinner than the first substrate.

[D05] The display device according to any one of [D01] to [D04], inwhich the light control device is constituted by an optical shutter inwhich a light transmission control material layer includes a liquidcrystal material layer.

[D06] The display device according to any one of [D01] to [D04], inwhich the light control device is constituted by an optical shutter inwhich a light transmission control material layer includes an inorganicelectroluminescence material layer.

[D07] The display device according to any one of [D01] to [D06], furtherincluding an environmental illuminance measuring sensor for measuringilluminance of an environment where the display device is placed, inwhich the display device controls a light transmittance of the lightcontrol device or controls brightness of an image formed by the imageforming device on the basis of a measurement result of the environmentalilluminance measuring sensor.

[D08] The display device according to any one of [D01] to [D07], furtherincluding a transmitted light illuminance measuring sensor for measuringilluminance based on light which has passed through the light controldevice from an external environment, in which the display devicecontrols a light transmittance of the light control device and/orcontrols brightness of an image formed by the image forming device onthe basis of a measurement result of the transmitted light illuminancemeasuring sensor.

[D09] The display device according to [D08], in which the transmittedlight illuminance measuring sensor is disposed closer to an observerthan the light guide device.

[D10] The display device according to any one of [D01] to [D09], inwhich a first deflecting unit and a second deflecting unit are coveredby one of substrates constituting the light control device.

[D11] The display device according to any one of [D01] to [D10], inwhich the second deflecting unit is located in a projected image of thelight control device, or the light control device is located in aprojected image of the second deflecting unit.

[E01] The display device according to any one of [B01] to [D11], inwhich a light shielding member for shielding external light incident onthe light guide device is disposed on the opposite side to an observerwith the light guide device as a reference.

[E02] The display device according to any one of [B01] to [D11], inwhich a light shielding member for shielding external light incident onthe light guide device is disposed in a region of the light guide deviceon which light emitted from the image forming device is incident.

[E03] The display device according to [E01] or [E02], in which theregion of the light guide device on which light emitted from the imageforming device is incident is included in a projected image of the lightshielding member on the light guide device.

[E04] The display device according to any one of [E01] to [E03], inwhich the light shielding member is disposed away from the light guidedevice on the opposite side to an observer with the light guide deviceas a reference.

[E05] The display device according to any one of [E01] to [E04], inwhich the light shielding member is disposed in a portion of the lightguide device on the opposite side to an observer with the light guidedevice as a reference.

[E06] The display device according to any one of [E01] to [E05], inwhich

-   -   a light shielding member for shielding external light incident        on the light guide device is disposed in a region of the light        guide device on which light emitted from the image forming        device is incident, and    -   a projected image of an end portion of the light control device        on the light guide device is included in a projected image of        the light shielding member on the light guide device.

[E07] The display device according to any one of [C01] to [D11], inwhich

-   -   a light shielding member for shielding external light incident        on the light guide device is disposed in a region of the light        guide device on which light emitted from the image forming        device is incident, and    -   the light shielding member is disposed in the light control        device.

[F01] <<Method for manufacturing light emitting element>>

-   -   A method for manufacturing a light emitting element, the method        including steps of:    -   forming a laminated structure including at least one layer of a        light emitting laminate including a first electrode, a second        electrode, and a light emitting layer provided between the first        electrode and the second electrode; then forming an        antireflection layer on the laminated structure; and    -   then forming a through hole for emitting light from the light        emitting layer toward an outside in the antireflection layer and        the laminated structure in a lamination direction of the        laminated structure.

[G01] <<Light emitting element>>

-   -   A light emitting element including a laminated structure        including at least one layer of a light emitting laminate        including a first electrode, a second electrode, and a light        emitting layer provided between the first electrode and the        second electrode, in which    -   in the laminated structure, a through hole formed in a        lamination direction of the laminated structure for emitting        light from the light emitting layer to an outside is formed, and    -   an antireflection layer is formed in the laminated structure on        a light emitting side.

[G02] The light emitting element according to [G01], in which theantireflection layer is formed up to an edge portion of the through holein the laminated structure.

REFERENCE SIGNS LIST

-   10 Frame-   10′ Nose pad-   11 Front portion-   11′ Central portion of front portion-   12 Hinge-   13 Temple portion-   14 Modern portion-   15 Wiring (signal line, power supply line, or the like)-   16 Headphone portion-   16′ Headphone portion wiring-   17 Imaging device-   18 Control device (control circuit or control unit)-   18A Image information storage device-   19 Attachment member-   20 Observer-   21 Pupil-   100A, 100B, 200A, 200B Image display device-   111, 111′ Image forming device-   114, 114′ Lens system-   115 Casing-   120, 130, 220, 230 Light guide device-   121, 131 Light guide plate-   121A, 131A First surface of light guide plate-   121 B, 131 B Second surface of light guide plate-   122, 132 First deflecting unit-   123, 133, 223 Second deflecting unit-   122 a, 123 a Interference fringe-   124 Transparent protective member-   125 Sealing member-   221 Transparent member-   231 Glass plate-   233 Semi-transmissive mirror-   300 Light emitting element-   301 Laminated structure-   310, 320, 330 Light emitting laminate (first light emitting    laminate, second light emitting laminate, or third light emitting    laminate)-   311, 321, 331 Light emitting layer-   312A, 322A, 332A First electrode-   312B, 322B, 332B Second electrode-   312 a, 312 b, 322 a, 322 b, 332 a, 332 b Contact portion-   341 First insulating layer-   342 Second insulating layer-   343 Third insulating layer-   344 Fourth insulating layer-   351 Support substrate-   351A Surface of support substrate-   352 Second support substrate-   360 Through hole-   361 Core portion-   362 Clad layer-   363 Condenser lens-   370 Antireflection layer (light absorbing layer)-   371 Protective film-   380 Separation groove-   390 Circuit board-   401, 402 Light shielding member-   500 Light control device-   501 First substrate (transparent protective member also serves as    first substrate)-   502 First transparent electrode-   502A First transparent electrode segment-   503 Second substrate-   504 Second transparent electrode-   504A Second transparent electrode segment-   505 Light control layer-   505A WO₃ layer-   505B Ta₂O₅ layer-   505C Ir_(X)Sn_(1-X)O layer-   506 Protective layer-   507 Sealing material-   508 Minimum unit region in which light shielding ratio of light    control device changes-   511 Virtual image projection region-   512 Another region of light control device-   513 Virtual rectangle-   521 Environmental illuminance measuring sensor-   522 Transmitted light illuminance measuring sensor-   612 Light guide member-   613 Semi-transmissive mirror-   614 Reflecting plate-   622 Prism-   623, 624 Prism surface-   625 Convex lens-   CL Central light beam

1. An optical device, comprising: an image forming device that includes a plurality of light emitting elements, wherein each of the plurality of light emitting elements includes a through hole, a first electrode, a second electrode, and a light emitting layer between the first electrode and the second electrode; a lens system configured to project an image from the image forming device on an outside of the optical device; and wherein the light emitting layer is configured to emit light toward the lens system via the through hole.
 2. The optical device according to claim 1, wherein the lens system is further configured to reflect the light.
 3. The optical device according to claim 1, wherein each of the plurality of light emitting elements further includes: an antireflection layer in a portion of the laminated structure, and a condenser lens on the antireflection layer, and the antireflection layer faces the lens system such that the light reflected by the lens system is not reflected by the image forming device.
 4. The optical device according to claim 1, wherein the antireflection layer is up to an edge portion of the through hole in the laminated structure.
 5. The optical device according to claim 1, wherein the plurality of the light emitting laminate includes one of: a first light emitting element configured to emit red light, a second light emitting element configured to emit green light, or a third light emitting element configured to emit blue light.
 6. The optical device according to claim 3, wherein the condenser lens is configured to condense the light emitted via the through hole.
 7. The optical device according to claim 1, wherein the image forming device further includes a circuit board, the optical device further includes a light emitting element driving circuit on the circuit board, and each light emitting element of the plurality of light emitting elements is connected to the light emitting element driving circuit.
 8. The optical device according to claim 1, wherein the image forming device further includes a support substrate, and the support substrate is on the second electrode.
 9. A display device, comprising: a frame mounted on a head of an observer; and an image display device attached to the frame, wherein the image display device includes: an image forming device that includes a plurality of light emitting elements, wherein each of the plurality of light emitting elements includes a through hole, a first electrode, a second electrode, and a light emitting layer between the first electrode and the second electrode; a lens system configured to project an image from the image forming device on an outside of the optical device; and wherein the light emitting layer is configured to emit light toward the lens system via the through hole.
 10. The display device according to claim 9, wherein the lens system is further configured to reflect the light.
 11. The display device according to claim 9, wherein each of the plurality of light emitting elements further includes: an antireflection layer in a portion of the laminated structure, and a condenser lens on the antireflection layer, and the antireflection layer faces the lens system such that the light reflected by the lens system is not reflected by the image forming device.
 12. The display device according to claim 9, wherein the antireflection layer is up to an edge portion of the through hole in the laminated structure.
 13. The display device according to claim 9, wherein the plurality of the light emitting laminate includes one of: a first light emitting element configured to emit red light, a second light emitting element configured to emit green light, or a third light emitting element configured to emit blue light.
 14. The display device according to claim 11, wherein the condenser lens is configured to condense the light emitted via the through hole.
 15. The display device according to claim 9, wherein the image forming device further includes a circuit board, the optical device further includes a light emitting element driving circuit on the circuit board, and each light emitting element of the plurality of light emitting elements is connected to the light emitting element driving circuit.
 16. The display device according to claim 9, wherein the image forming device further includes a support substrate, and the support substrate is on the second electrode. 